Some environments are just custom unity assets. You can try adding one to the scene and see if you can find the file for the environment there. Another way would be to merge load the scenes. Strip everything you don't need from each scene and merge load them. Of course you may need to move around some things after. Also disable collision on the people so they dont explode if you try to merge a person onto a wall or something. I'm sure this is all very confusing, lol, don't worry there's almost always a way in vam.