Find the Index-View just below the Topicmaps loaded-View. The Index-View gives you access to several indexes of the current topicmap.

After a new topicmap is loaded, it becomes automatically the current topicmap. This causes the Index-View to switch to an index of this topicmap automatically.

The dropdown list at the top of the Index-View let you select the index being displayed. See Index-View for an overview which indexes are available.

The Index-View, used to display two different indexes

Selecting an entry of an index causes that element to be displayed in the two views on the right... proceed -> The Renderer-Views