diff --git a/classifier/css/layout.css b/classifier/css/layout.css
index 3f59fca..c0ce6e8 100644
--- a/classifier/css/layout.css
+++ b/classifier/css/layout.css
@@ -405,8 +405,9 @@
     background: var(--primary); color: var(--bg);
     border-radius: 999px; padding: 0 0.4rem; font-size: 0.7rem; font-weight: 600;
 }
-.tnode__actions { margin-left: auto; display: inline-flex; gap: 0.1rem; opacity: 0; transition: opacity 0.12s; }
-.tnode__row:hover .tnode__actions, .tslot__row:hover .tnode__actions { opacity: 1; }
+/* Node CRUD controls sit to the LEFT of the level name (always visible) so
+   building/pruning the tree is a one-click affordance, not a hover-hunt. */
+.tnode__actions { display: inline-flex; gap: 0.1rem; margin-right: 0.15rem; flex: 0 0 auto; }
 .tnode__act {
     border: 1px solid var(--border); background: var(--bg);
     border-radius: var(--radius); cursor: pointer;
diff --git a/classifier/js/app.js b/classifier/js/app.js
index 3afc440..48a60eb 100644
--- a/classifier/js/app.js
+++ b/classifier/js/app.js
@@ -142,7 +142,10 @@
             exportHashesBtn: document.getElementById('exportHashesBtn'),
             sha256Checkbox: document.getElementById('sha256Checkbox'),
             hideCompliantCheckbox: document.getElementById('hideCompliantCheckbox'),
-            
+            hideCompliantLabel: document.getElementById('hideCompliantLabel'),
+            hideAssignedCheckbox: document.getElementById('hideAssignedCheckbox'),
+            hideAssignedLabel: document.getElementById('hideAssignedLabel'),
+
             // Folder tree
             folderTree: document.getElementById('folderTree'),
             folderTreePane: document.getElementById('folderTreePane'),
@@ -183,6 +186,10 @@
         app.dom.modeClassifyBtn.classList.toggle('active', classify);
         if (app.dom.spreadsheetPane) app.dom.spreadsheetPane.hidden = classify;
         if (app.dom.targetPane) app.dom.targetPane.hidden = !classify;
+        // Mode-specific source-tree filters: "Hide Compliant" is for the rename
+        // grid; "Hide Assigned" is for the classify workflow.
+        if (app.dom.hideCompliantLabel) app.dom.hideCompliantLabel.hidden = classify;
+        if (app.dom.hideAssignedLabel) app.dom.hideAssignedLabel.hidden = !classify;
         app.modules.classify.setEnabled(classify);
         if (classify && app.modules.targetTree) {
             app.modules.targetTree.init();
@@ -215,7 +222,16 @@
         
         // Hide compliant toggle
         app.dom.hideCompliantCheckbox.addEventListener('change', handleHideCompliantToggle);
-        
+
+        // Hide assigned toggle (classify mode — filters the source tree)
+        if (app.dom.hideAssignedCheckbox) {
+            app.dom.hideAssignedCheckbox.addEventListener('change', function () {
+                if (app.modules.tree && app.modules.tree.setHideAssigned) {
+                    app.modules.tree.setHideAssigned(this.checked);
+                }
+            });
+        }
+
         // Collapse tree button
         app.dom.collapseTreeBtn.addEventListener('click', handleCollapseTree);
 
diff --git a/classifier/js/classify.js b/classifier/js/classify.js
index 824636e..fc2b286 100644
--- a/classifier/js/classify.js
+++ b/classifier/js/classify.js
@@ -394,6 +394,61 @@
         notify();
     }
 
+    // ── add-folder pattern expansion ─────────────────────────────────────────
+    // Brace expansion for the add-folder box. Supports (non-nested) groups:
+    //   {a,b,c}      → alternation: a | b | c
+    //   {0001-0002}  → numeric range, zero-padded to the operands' width
+    //   {0001-0002,0005} → mix ranges and literals in one group
+    // Multiple groups expand as a cartesian product, e.g.
+    //   "X-{PM,EL}-{0001-0002,0005}_A (IFR)" → 6 names.
+    // A pattern with no braces returns itself (one name). Unbalanced braces are
+    // treated literally so the user never silently loses input.
+    function expandGroup(body) {
+        var out = [];
+        String(body).split(',').forEach(function (piece) {
+            var m = /^\s*(\d+)\s*-\s*(\d+)\s*$/.exec(piece);
+            if (m) {
+                var a = m[1], b = m[2];
+                var start = parseInt(a, 10), end = parseInt(b, 10);
+                // Pad when either operand carries a leading zero (e.g. 0001).
+                var width = (a.length > 1 && a[0] === '0') || (b.length > 1 && b[0] === '0')
+                    ? Math.max(a.length, b.length) : 0;
+                var step = start <= end ? 1 : -1;
+                for (var v = start; step > 0 ? v <= end : v >= end; v += step) {
+                    out.push(width ? String(v).padStart(width, '0') : String(v));
+                }
+            } else {
+                out.push(piece);
+            }
+        });
+        return out;
+    }
+    function expandFolderPattern(pattern) {
+        var s = String(pattern == null ? '' : pattern);
+        var parts = [];                 // each: {lit} or {opts:[...]}
+        var i = 0;
+        while (i < s.length) {
+            var open = s.indexOf('{', i);
+            if (open === -1) { parts.push({ lit: s.slice(i) }); break; }
+            var close = s.indexOf('}', open);
+            if (close === -1) { parts.push({ lit: s.slice(i) }); break; } // unbalanced → literal
+            if (open > i) parts.push({ lit: s.slice(i, open) });
+            parts.push({ opts: expandGroup(s.slice(open + 1, close)) });
+            i = close + 1;
+        }
+        var results = [''];
+        parts.forEach(function (p) {
+            var opts = p.lit != null ? [p.lit] : p.opts;
+            var next = [];
+            results.forEach(function (prefix) {
+                opts.forEach(function (o) { next.push(prefix + o); });
+            });
+            results = next;
+        });
+        // Trim + drop empties so a stray comma can't create a blank folder.
+        return results.map(function (r) { return r.trim(); }).filter(Boolean);
+    }
+
     // ── mode ─────────────────────────────────────────────────────────────────
     function setEnabled(on) { state.enabled = !!on; notify(); }
     function isEnabled() { return state.enabled; }
@@ -412,6 +467,7 @@
         // trees
         addTrackingNode: addTrackingNode, addParty: addParty,
         addTransmittalBin: addTransmittalBin, renameNode: renameNode, deleteNode: deleteNode,
+        expandFolderPattern: expandFolderPattern,
         getNode: getNode, getTrackingTree: function () { return state.trackingTree; },
         getTransmittalTree: function () { return state.transmittalTree; },
         // derive + reverse
diff --git a/classifier/js/target-tree.js b/classifier/js/target-tree.js
index cb7b39f..ce7e763 100644
--- a/classifier/js/target-tree.js
+++ b/classifier/js/target-tree.js
@@ -19,6 +19,7 @@
     var collapsed = {};            // nodeId -> true when collapsed (default expanded)
     var openForm = null;           // { partyId, slot } when a bin form is open
     var initialized = false;
+    var currentTab = 'tracking';   // 'tracking' | 'transmittal' — the active axis
 
     function init() {
         if (initialized) return;
@@ -38,8 +39,9 @@
         els.trackingTab.addEventListener('click', function () { showTab('tracking'); });
         els.transmittalTab.addEventListener('click', function () { showTab('transmittal'); });
         els.addTrackingRootBtn.addEventListener('click', function () {
-            var name = prompt('Root folder name (a tracking-number segment, e.g. "ACME-PROJ"):', '');
-            if (name && name.trim()) C().addTrackingNode(null, name.trim());
+            var name = prompt('Root folder name (a tracking-number segment, e.g. "ACME-PROJ").\n'
+                + 'Brace patterns expand: BMB-{PM,EL}-{0001-0002,0005}_A (IFR)', '');
+            addFoldersFromPattern(null, name);
         });
         els.addPartyBtn.addEventListener('click', function () {
             var name = prompt('Party name (also the transmittal-number prefix):', '');
@@ -86,10 +88,29 @@
 
     function showTab(which) {
         var t = which === 'transmittal';
+        currentTab = t ? 'transmittal' : 'tracking';
         els.trackingTab.classList.toggle('active', !t);
         els.transmittalTab.classList.toggle('active', t);
         els.trackingPanel.hidden = t;
         els.transmittalPanel.hidden = !t;
+        // The "Hide Assigned" filter on the source tree is per-axis, so the
+        // visible set changes with the active tab — re-render the left tree.
+        if (window.app.modules.tree && window.app.modules.tree.render) window.app.modules.tree.render();
+    }
+    function activeAxis() { return currentTab === 'transmittal' ? 'transmittal' : 'tracking'; }
+
+    // Expand a brace pattern into folder names and create them (confirming a
+    // multi-create first). parentId null = root folders. See expandFolderPattern.
+    function addFoldersFromPattern(parentId, raw) {
+        if (!raw || !raw.trim()) return;
+        var names = C().expandFolderPattern(raw);
+        if (!names.length) return;
+        if (names.length > 1) {
+            var shown = names.slice(0, 8).join('\n');
+            if (names.length > 8) shown += '\n…and ' + (names.length - 8) + ' more';
+            if (!confirm('Create ' + names.length + ' folders?\n\n' + shown)) return;
+        }
+        names.forEach(function (nm) { C().addTrackingNode(parentId, nm); });
     }
 
     // ── render ───────────────────────────────────────────────────────────────
@@ -166,16 +187,15 @@
         var toggle = el('button', 'tnode__toggle', isLeaf ? '·' : (collapsed[n.id] ? '▸' : '▾'));
         if (!isLeaf) toggle.dataset.act = 'toggle';
         row.appendChild(toggle);
-        row.appendChild(el('span', 'tnode__name', n.name));
-
-        var placed = placedMap[n.id] || [];
-        if (placed.length) row.appendChild(el('span', 'tnode__badge', String(placed.length)));
-
         row.appendChild(nodeActions([
             { act: 'add', label: '＋', title: 'Add child folder' },
             { act: 'rename', label: '✎', title: 'Rename' },
             { act: 'del', label: '🗑', title: 'Delete' },
         ]));
+        row.appendChild(el('span', 'tnode__name', n.name));
+
+        var placed = placedMap[n.id] || [];
+        if (placed.length) row.appendChild(el('span', 'tnode__badge', String(placed.length)));
         wrap.appendChild(row);
 
         if (placed.length) wrap.appendChild(fileList(placed));
@@ -201,11 +221,11 @@
         wrap.dataset.id = party.id;
         var row = el('div', 'tnode__row');
         row.appendChild(el('span', 'tnode__icon', '🏢'));
-        row.appendChild(el('span', 'tnode__name', party.name));
         row.appendChild(nodeActions([
             { act: 'rename-party', label: '✎', title: 'Rename party' },
             { act: 'del-party', label: '🗑', title: 'Delete party' },
         ]));
+        row.appendChild(el('span', 'tnode__name', party.name));
         wrap.appendChild(row);
 
         SLOTS.forEach(function (slot) {
@@ -234,10 +254,10 @@
         var wrap = el('div', 'tnode tnode--bin');
         wrap.dataset.id = bin.id;
         var row = el('div', 'tnode__row');
+        row.appendChild(nodeActions([{ act: 'del', label: '🗑', title: 'Delete transmittal' }]));
         row.appendChild(el('span', 'tnode__name', bin.name || '(invalid — set date/seq)'));
         var placed = placedMap[bin.id] || [];
         if (placed.length) row.appendChild(el('span', 'tnode__badge', String(placed.length)));
-        row.appendChild(nodeActions([{ act: 'del', label: '🗑', title: 'Delete transmittal' }]));
         wrap.appendChild(row);
         if (placed.length) wrap.appendChild(fileList(placed));
         return wrap;
@@ -283,8 +303,9 @@
         var id = closestNodeId(btn);
         if (act === 'toggle') { collapsed[id] = !collapsed[id]; render(); return; }
         if (act === 'add') {
-            var name = prompt('Child folder name (next tracking segment, or a leaf revision like "A (IFR)"):', '');
-            if (name && name.trim()) C().addTrackingNode(id, name.trim());
+            var name = prompt('Child folder name (next tracking segment, or a leaf revision like "A (IFR)").\n'
+                + 'Brace patterns expand: {PM,EL,EM}-MOM-{0001-0002,0005}_A (IFR)', '');
+            addFoldersFromPattern(id, name);
         } else if (act === 'rename') {
             var node = C().getNode(id);
             var nn = prompt('Rename folder:', node ? node.name : '');
@@ -396,6 +417,7 @@
         init: init,
         render: render,
         showTab: showTab,
+        activeAxis: activeAxis,
         reveal: reveal,
     };
 })();
diff --git a/classifier/js/tree.js b/classifier/js/tree.js
index 1f49466..985fc73 100644
--- a/classifier/js/tree.js
+++ b/classifier/js/tree.js
@@ -35,6 +35,37 @@
         return dot;
     }
 
+    // ── "Hide Assigned" filter (classify mode) ─────────────────────────────
+    // The goal in either target tab is to assign-or-exclude every file, so this
+    // collapses the left tree down to only what's left to deal with on the
+    // ACTIVE axis: hide files already assigned in the current tab (or excluded),
+    // and any folder whose whole (scanned) subtree is thereby empty.
+    var hideAssigned = false;
+    function setHideAssigned(on) { hideAssigned = !!on; render(); }
+    function activeAxis() {
+        var tt = window.app.modules.targetTree;
+        return (tt && tt.activeAxis) ? tt.activeAxis() : 'tracking';
+    }
+    function fileDealtWith(file) {
+        var c = window.app.modules.classify;
+        var a = c.getAssignment(c.srcKeyForFile(file));
+        if (!a) return false;
+        if (a.excluded) return true;
+        return activeAxis() === 'transmittal' ? !!a.transmittalNodeId : !!a.trackingNodeId;
+    }
+    function subtreeRemaining(folder) {
+        var n = 0;
+        subtreeFiles(folder).forEach(function (f) { if (!fileDealtWith(f)) n++; });
+        return n;
+    }
+    // Hide a folder only when it's fully scanned (so we never hide one that may
+    // still reveal files) and nothing in its subtree remains to be dealt with.
+    function folderHidden(folder) {
+        if (!classifyOn() || !hideAssigned) return false;
+        if (folder.scanState && folder.scanState !== 'done') return false;
+        return subtreeRemaining(folder) === 0;
+    }
+
     /**
      * Render the folder tree
      */
@@ -49,6 +80,7 @@
         }
 
         window.app.folderTree.forEach(folder => {
+            if (folderHidden(folder)) return;
             const element = createFolderElement(folder);
             container.appendChild(element);
         });
@@ -241,6 +273,7 @@
             const childrenDiv = document.createElement('div');
             childrenDiv.className = 'folder-children';
             folder.children.forEach(child => {
+                if (folderHidden(child)) return;
                 const childElement = createFolderElement(child, level + 1);
                 childrenDiv.appendChild(childElement);
             });
@@ -253,6 +286,7 @@
             const filesDiv = document.createElement('div');
             filesDiv.className = 'folder-children folder-files';
             folder.files.forEach(function (file) {
+                if (hideAssigned && fileDealtWith(file)) return;
                 filesDiv.appendChild(createFileElement(file, level + 1));
             });
             div.appendChild(filesDiv);
@@ -829,6 +863,7 @@
         setupKeyboardShortcuts,
         expandAll,
         selectAll,
-        revealFile
+        revealFile,
+        setHideAssigned
     };
 })();
diff --git a/classifier/template.html b/classifier/template.html
index 290f85c..c03d3cc 100644
--- a/classifier/template.html
+++ b/classifier/template.html
@@ -57,10 +57,15 @@
                                 <input type="checkbox" id="autoScrollCheckbox" checked>
                                 Auto-scroll
                             </label>
-                            <label class="checkbox-label">
+                            <label class="checkbox-label" id="hideCompliantLabel">
                                 <input type="checkbox" id="hideCompliantCheckbox">
                                 Hide Compliant
                             </label>
+                            <label class="checkbox-label" id="hideAssignedLabel" hidden
+                                   title="Hide files already assigned in the active tab (or excluded), and folders left empty">
+                                <input type="checkbox" id="hideAssignedCheckbox">
+                                Hide Assigned
+                            </label>
                             <span id="selectedFoldersCount" class="folder-count">0 folders selected</span>
                         </div>
                     </div>
diff --git a/tests/classify.spec.js b/tests/classify.spec.js
index b9bcaaf..20c7888 100644
--- a/tests/classify.spec.js
+++ b/tests/classify.spec.js
@@ -532,3 +532,54 @@ test('deleting a tracking node clears the files placed in it', async ({ page })
     }, FILE);
     expect(after).toBe('none');
 });
+
+test('expandFolderPattern: alternation, zero-padded ranges, cartesian product', async ({ page }) => {
+    const r = await page.evaluate(() => {
+        const c = window.app.modules.classify;
+        return {
+            plain: c.expandFolderPattern('Plain'),
+            alt: c.expandFolderPattern('A-{PM,EL,EM}'),
+            range: c.expandFolderPattern('X-{0001-0002,0005}'),
+            full: c.expandFolderPattern('BMB-187023-{PM,EL,EM}-MOM-{0001-0002,0005}_A (IFR)'),
+            unbalanced: c.expandFolderPattern('Lit-{oops'),
+        };
+    });
+    expect(r.plain).toEqual(['Plain']);
+    expect(r.alt).toEqual(['A-PM', 'A-EL', 'A-EM']);
+    expect(r.range).toEqual(['X-0001', 'X-0002', 'X-0005']);
+    expect(r.full.length).toBe(9);
+    expect(r.full[0]).toBe('BMB-187023-PM-MOM-0001_A (IFR)');
+    expect(r.full).toContain('BMB-187023-EM-MOM-0005_A (IFR)');
+    expect(r.unbalanced).toEqual(['Lit-{oops']); // unbalanced brace kept literal
+});
+
+test('Hide Assigned: hides files dealt-with on the active axis and folders left empty', async ({ page }) => {
+    await page.click('#modeClassifyBtn');
+    const before = await page.evaluate(() => {
+        const c = window.app.modules.classify;
+        c.reset();
+        const fA = { originalFilename: 'a1', extension: 'pdf', folderPath: 'A' };
+        window.app.folderTree = [
+            { name: 'A', path: 'A', expanded: true, scanState: 'done', files: [fA], children: [] },
+            { name: 'B', path: 'B', expanded: true, scanState: 'done',
+              files: [{ originalFilename: 'b1', extension: 'pdf', folderPath: 'B' }], children: [] },
+        ];
+        const t = c.addTrackingNode(null, 'TN');     // assign A's file on the tracking axis
+        c.place([c.srcKeyForFile(fA)], t, 'tracking');
+        window.app.modules.tree.render();
+        return document.querySelectorAll('#folderTree .file-item').length;
+    });
+    expect(before).toBe(2);                          // nothing hidden yet
+
+    const after = await page.evaluate(() => {
+        window.app.modules.tree.setHideAssigned(true);
+        return {
+            files: Array.from(document.querySelectorAll('#folderTree .file-item .file-name')).map(e => e.textContent),
+            folderA: !!document.querySelector('#folderTree .folder-item[data-path="A"]'),
+            folderB: !!document.querySelector('#folderTree .folder-item[data-path="B"]'),
+        };
+    });
+    expect(after.folderA).toBe(false);   // A's only file is assigned on the active (tracking) axis → folder hidden
+    expect(after.folderB).toBe(true);    // B still needs a tracking number → stays
+    expect(after.files).toEqual(['b1.pdf']);
+});