The best navigation method in New Graph scene is manipulations of items in one main scene, as roku's says:
Engineering's Response:
So you can create the “illusion” of having multiple Scenes by selectively making the current “scene” invisible and replacing it (appending) another component, then “go back” when needed by removing/disappearing the component “scene” and making the original “scene” visible again (not unheard of for UI programming, in fact). Again, you probably want to use your Scene node as your “master control” node.
http://forums.roku.com/viewtopic.php?f=34&t=88621&start=90