there is a extreme and very good example of slideouts which i designed for a asiatic car company, the maxus v90 villa edition. we could even leave the first floor free without bed and eating place, but relocate it to the slideouts at the top, building a second floor. the bed and eating/sitting area would be at a top. the drivers cabin would function as a balcony and viewpoint. if we need an elevated position of view, we could go on the top of the drivers cabin by ladder on the side or on standing position trough the elevator.
https://www.youtube.com/watch?v=IZ7lrBlBdzY