You’re trying to make something like this?
Basically you’re making 3 screens. You allow for overlapping widgets in Nova. You also set screen transition to wipe.
Whatever is on screen 2 you also have on screens 1 and 3. On screen 1 you place one side bar over the top of all else. The opposite on screen 3. The overlapping and the wipe give the illusion of sidebars sliding in.