The Edit menu lists choices corresponding to each type of relationship the selected construct has with other constructs in the parse tree. If you select a variable in the Source pane, for example, the Edit menu shows Conditions, Port, and Declaration choices. The choices are grayed-out if no relationships of the given type exist for the selected construct.
To view all the constructs in the source file that have a given relationship with a construct, select the construct in the Source pane and choose the appropriate relationship in the Edit menu: