The graph area in the menus view is similar to the graph area in the layouts view. It displays, in graph form, the menu system that has been defined for the current interface. Menu items are displayed as the children of menus or menu components, which in turn are displayed as the children of other menus, or of the entire menu bar.
Like the layouts view, a new menu element is added as the child of the currently selected item in the graph, or the last selected element if nothing is currently selected.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011