awesome, thanks for taking a swing at that for me. Not quite what i was looking for but that is my fault really for not giving more info on my project.
I am making a top down rpg where players acquire suits that let them travel underground and underwater. I am using 8 dir movement behavior. when the player is wearing a suit that can go underground for instance they click a button and all the surface objects are hidden and the underground objects are made visible and collisions enabled. i do not want them to be able to leave the tiled area as that might be into water or something. it would be nice to have a black layer behind the walkable layer that the player cannot go to. I am hoping to not have to create a barrier object to line the whole map with because I would have to do it for each layer which would be a little tedious.
I am totally holding onto that example for future mechanics in my game though, that is pretty cool.