A standard menu component can be used to group related menu commands that would otherwise be placed as direct children of the menu bar they populate. This offers several advantages.
Click Component in the button bar to add a standard menu component to the current interface. Menu components must be added as the children of a menu. Menu components are not visible in the interface skeleton until at least one item or submenu has been added, using the Item or Menu buttons.
Menu items added to a standard menu component appear as standard menu items in that component.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011