This is how mine use to be set up.
The platform you see there folds up to a 90 degree angle, and the legs hinged in/down, storage underneath obviously. I kept two other pieces the platform underneath that one, that extended all the way to the other side for two people.
Worked well for me, but I ended up throwing all of it in the dump after a few years. I made it the whole deal in two pieces so it was relatively easy to remove, but it just got old taking it out to hual stuff.
I had plans to make a more simple platform all the way across, on top of the wheel wells, with fullsize spare underneath in the front, and pull out drawers in the back. Just never bothered with it as I don't use it much for sleeping lately. Too cramped for two people.