Abstract: Navigation of a hierarchical system is facilitated by a specialized graphical user interface in which graphical representations of different levels of the hierarchy are mapped to and coordinate with menu controls. The graphical representation may variously describe the topological arrangement of a hierarchy or a functional representation of a hierarchical system. Selecting an element of the graphical representation causes a new representation to appear, showing higher level of detail of the selected element. Simultaneously the menu controls expand to offer submenus corresponding to the greater detail for selection by a user. The graphical representation may be augmented by other controls, such as shortcut icons for enhanced performance.