Layer › Ungroup Layers (Ctrl+Shift+G), in a folder's menu too; Alt over a mask shows the eye pointer (13.15)

src/Document/LayerGroups+Session.h

@@ -7,6 +7,9 @@ public:
     void selectLayers(const QSet<QUuid> &ids, std::optional<QUuid> primary);
     void extendSelection(QUuid id);
     void groupSelectedLayers();
+    // The active layer is a folder: something to unwrap.
+    bool canUngroupLayers() const;
+    void ungroupLayers();
     std::vector<LayerHierarchy::Entry> layerRows() const;
     bool canPlaceLayer(QUuid id, std::optional<QUuid> parent) const;
     bool placeLayer(QUuid id, std::optional<QUuid> parent, std::optional<QUuid> above = std::nullopt, bool atBottom = false);