The Relation Window is a Source Insight innovation that shows the relationship between the currently selected symbol and other things. The Relation Window can show function call trees, class hierarchies, structure members, reference trees, and more. It can be docked along side your source windows, and it works in the background tracking what you are selecting and showing relationship information automatically.
To show the Relation Window, select View > Panels > Relation Window.
You can specify the relationship types and many other options in the Relation Window Options dialog. See: Relation Window Options.
The Relation Window runs in the background and tracks what symbols you have selected. The beauty of the Relation Window is that you don’t have to do anything special. It works in the background while you work, but you can interact with it when you want to. You can also have several Relation Windows open, each showing different types of information.