Navigating an NGUI pause menu?

I studied the pause menu code in the wiki, and got that working fine. The game/project I'm working, however, is for the Oculus Rift, and upon some research, I found that NGUI is the best way to make UI that integrates well for the Rift (without having to write more code in my UI scripts).

So I created a simple pause menu uwing NGUI. When the player presses Escape, the game is paused and NGUITools.setActive is used to activate/deactivate the UI Root.

I used the example menu that NGUI provides for testing, but I can't seem to figure out how to go about navigating the menu. What I mean is, when I press the 'options' button, the menu goes to an options submenu where I can tweak volume, graphics, etc. How would I go about making it so that when I press escape, it goes back to the main pause menu instead of simply unpausing and going back to the game? How do I get the NGUI buttons/animations to integrate with my pause menu script (which is attached to the player controller)?