Is there a way to keep colliders sepearted from each other, so they do not collide when in same space?

I want to have 2 instances of two different worlds in the same location on XYZ in world space. I want the colliders in one world to not collide with the colliders in the second world. The colliders in one world would coincidently be in the same location as the colliders in two world.

My goal is to use Unity3d to create an MMO with only one unity3d application running. To have the number of worlds I want they must be all at 0,0,0 world space. When objects move around in each of the worlds they would coincidently collide. I want the colliders to be independent to each world of their own,. This would allow colliders in world one to pass through without collision detection into world two objects.

You can do layer based collision: Unity - Manual: Layer-based collision detection