diff --git a/multiace/i18n/de.json b/multiace/i18n/de.json
index a699c31a..5e9e447b 100644
--- a/multiace/i18n/de.json
+++ b/multiace/i18n/de.json
@@ -12,6 +12,7 @@
       "ws_error": "WS-Fehler"
     },
     "tabs": {
+      "print_hub": "Print Hub",
       "dashboard": "Übersicht",
       "dry": "Trocknen",
       "config": "Konfiguration",
diff --git a/multiace/i18n/en.json b/multiace/i18n/en.json
index ee3569f0..2ea0944d 100644
--- a/multiace/i18n/en.json
+++ b/multiace/i18n/en.json
@@ -12,6 +12,7 @@
       "ws_error": "WS error"
     },
     "tabs": {
+      "print_hub": "Print Hub",
       "dashboard": "Dashboard",
       "dry": "Dry",
       "config": "Config",
diff --git a/multiace/i18n/zh.json b/multiace/i18n/zh.json
index 4bdfb204..5503671a 100644
--- a/multiace/i18n/zh.json
+++ b/multiace/i18n/zh.json
@@ -12,6 +12,7 @@
       "ws_error": "WebSocket 错误"
     },
     "tabs": {
+      "print_hub": "打印中心",
       "dashboard": "控制台",
       "dry": "烘干",
       "config": "配置",
diff --git a/multiace/web/frontend/app.js b/multiace/web/frontend/app.js
index aa311303..b2d07fec 100644
--- a/multiace/web/frontend/app.js
+++ b/multiace/web/frontend/app.js
@@ -72,6 +72,55 @@ createApp({
       }
       return items;
     });
+    // Groups of tabs. An entry with `group: "<key>"` is a child of that group:
+    // the top bar shows ONE entry for the group (placed before the entry named
+    // in `before`) and a second row lists the children while one of them is
+    // open. A group with no children is not shown, so adding a feature's tab
+    // is the only thing that makes its group appear.
+    const NAV_GROUPS = [
+      {key: "printhub", labelKey: "ui.tabs.print_hub", before: "spools"},
+    ];
+    const groupLast = reactive({});
+    for (const g of NAV_GROUPS) {
+      try { groupLast[g.key] = localStorage.getItem("multiace.tabGroup." + g.key) || ""; }
+      catch (e) { groupLast[g.key] = ""; }
+    }
+    const groupOf = (key) => {
+      const it = navItems.value.find(i => i.key === key);
+      return it && it.group ? it.group : null;
+    };
+    const activeGroup = computed(() => groupOf(tab.value));
+    // Remember the last child opened in each group, per browser.
+    watch(tab, (v) => {
+      const g = groupOf(v);
+      if (!g) return;
+      groupLast[g] = v;
+      try { localStorage.setItem("multiace.tabGroup." + g, v); } catch (e) {}
+    });
+    const topItems = computed(() => {
+      const out = [];
+      const addGroup = (g) => {
+        const children = navItems.value.filter(i => i.group === g.key);
+        if (children.length) {
+          out.push({key: "group:" + g.key, group: g.key, children, label: t(g.labelKey)});
+        }
+      };
+      for (const it of navItems.value) {
+        if (it.group) continue;
+        for (const g of NAV_GROUPS) if (g.before === it.key) addGroup(g);
+        out.push(it);
+      }
+      return out;
+    });
+    const subItems = computed(() =>
+      activeGroup.value ? navItems.value.filter(i => i.group === activeGroup.value) : []);
+    const topActive = (it) => it.group ? activeGroup.value === it.group : tab.value === it.key;
+    // A group opens the child that was open last, else its first child.
+    function openNav(it) {
+      if (!it.group) { tab.value = it.key; return; }
+      const last = groupLast[it.group];
+      tab.value = (it.children.find(c => c.key === last) || it.children[0]).key;
+    }
     function pluginIframeSrc(p) {
       const u = (p && p.ui_url) || "/";
       return `/plugin/${p.name}${u.startsWith("/") ? u : "/" + u}`;
@@ -7435,7 +7484,7 @@ createApp({
       headPlanMapping, multiTopology, slotHead, pinLabel,
       updateState, updateCheck, updateApply,
       debugState, debugEnable, debugDisable,
-      navItems,
+      navItems, topItems, subItems, topActive, openNav,
       plugins, refreshPlugins, pluginIframeSrc,
       notifications, notifWarnOnly, notifTime, dismissNotification, dismissAllNotifications,
       confirmDialog, okConfirm, altConfirm, cancelConfirm, confirmInputError,
diff --git a/multiace/web/frontend/index.html b/multiace/web/frontend/index.html
index be857a84..fe32519c 100644
--- a/multiace/web/frontend/index.html
+++ b/multiace/web/frontend/index.html
@@ -311,8 +311,8 @@ <h1>m<span class="hl">U</span>lt<span class="hl">1</span>ACE
              :title="t('ui.common.firmware') + ' ' + printerFw">· {{ printerName }}</small>
     </h1>
     <nav>
-      <button v-for="it in navItems" :key="it.key"
-              :class="{active: tab===it.key}" @click="tab=it.key">{{ it.label }}</button>
+      <button v-for="it in topItems" :key="it.key"
+              :class="{active: topActive(it)}" @click="openNav(it)">{{ it.label }}</button>
     </nav>
     <input ref="uploadInput" type="file" accept=".gcode,.gco,.g"
            class="upload-input" @change="onUploadGcode($event.target.files)">
@@ -333,6 +333,13 @@ <h1>m<span class="hl">U</span>lt<span class="hl">1</span>ACE
     </button>
     <span class="conn" :class="connClass">{{ connText }}</span>
   </header>
+  <!-- Second row: the children of the open group (see NAV_GROUPS in app.js). -->
+  <div v-if="subItems.length && !panelMode" class="subnav">
+    <button v-for="it in subItems" :key="it.key"
+            :class="{active: tab===it.key}"
+            :aria-current="tab===it.key ? 'page' : null"
+            @click="tab=it.key">{{ it.label }}</button>
+  </div>
   <div v-if="rebootNeeded && !panelMode" class="reboot-banner">{{ t('ui.common.please_restart') }}</div>
   <div v-if="state.preflight_inbox?.pending && !panelMode" class="inbox-banner">
     <span>{{ t('ui.inbox.banner', {name: state.preflight_inbox?.name}) }}</span>
diff --git a/multiace/web/frontend/style-new.css b/multiace/web/frontend/style-new.css
index 86c7376f..e2534353 100644
--- a/multiace/web/frontend/style-new.css
+++ b/multiace/web/frontend/style-new.css
@@ -146,6 +146,20 @@ html[data-theme="new"] nav button.active {
   background: transparent; color: var(--nt-fg-strong); font-weight: 600;
   box-shadow: inset 0 -2px 0 var(--accent);
 }
+/* Second row: the children of the open tab group. Same underline marker as
+   the top bar, one step smaller. */
+html[data-theme="new"] .subnav {
+  gap: 0; padding: 0 20px; overflow-x: auto;
+  background: var(--bg); border-bottom: 1px solid var(--border);
+}
+html[data-theme="new"] .subnav button {
+  background: transparent; border: 0; border-radius: 0; padding: 10px 16px;
+  font-size: 13px; font-weight: 500; color: var(--muted); white-space: nowrap;
+}
+html[data-theme="new"] .subnav button:hover { color: var(--fg); }
+html[data-theme="new"] .subnav button.active {
+  color: var(--nt-fg-strong); font-weight: 600; box-shadow: inset 0 -2px 0 var(--accent);
+}
 html[data-theme="new"] header .upload-btn {
   order: 5; margin-left: 0; border: 0; border-left: 1px solid var(--border); border-radius: 0;
   background: var(--accent); color: var(--accent-fg);
@@ -559,6 +573,8 @@ html[data-theme="new"] .toolhead-card.nt-head .toolhead-actions { grid-area: act
     order: 6; flex: 1 1 100%; overflow-x: auto; border-top: 1px solid var(--border);
   }
   html[data-theme="new"] header nav button { padding: 12px 14px; white-space: nowrap; }
+  html[data-theme="new"] .subnav { padding: 0 8px; }
+  html[data-theme="new"] .subnav button { min-height: 44px; padding: 12px 14px; }
   html[data-theme="new"] header .conn { margin-left: 0; min-height: 44px; }
   html[data-theme="new"] header .upload-btn { min-height: 44px; }
   html[data-theme="new"] main { padding: 0 12px 16px; }
diff --git a/multiace/web/frontend/style.css b/multiace/web/frontend/style.css
index 257302ce..4a837709 100644
--- a/multiace/web/frontend/style.css
+++ b/multiace/web/frontend/style.css
@@ -94,6 +94,22 @@ nav button {
 }
 nav button:hover { border-color: var(--accent); }
 nav button.active { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
+/* Second row: the children of the open tab group. */
+.subnav {
+  display: flex; gap: .3rem; padding: .4rem 1rem; overflow-x: auto;
+  border-bottom: 1px solid var(--border); background: var(--card);
+}
+.subnav button {
+  background: transparent; color: var(--fg);
+  border: 1px solid var(--border);
+  padding: .3rem .8rem; cursor: pointer;
+  border-radius: 4px; font-size: .85rem; white-space: nowrap;
+}
+.subnav button:hover { border-color: var(--accent); }
+.subnav button.active { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
+@media (max-width: 700px) {
+  .subnav button { min-height: 44px; }
+}
 .upload-input { display: none; }
 .upload-btn {
   margin-left: auto;