Pops the Source Pane’s dive stack so that you return to the place you were previously at in the Source Pane. The dive stack is a history of the source locations you have visited while examining information. This command is analogous to the “Back” button in a browser in that it returns you to a previous position. Each time you “undive”, you pop one live off the dive stack.
As an alternative, you can select the “<” icon above and to the right of the Source Pane’s title.