Creating layers of meshes on a character that "slides" over one another ...

I am watching making of the characters in Uncharted 4 and they talk about creating a base mesh and then creating layers on top of that like the skins and wrinkles.
So I am just wondering how they do that.
In Unreal collisions on dynamic actors come from bones not the meshes themselves unless you give the mesh cloth properties.
So how would you build that in Unreal 4?
Can you build a lower res “base mesh” for a face and then add a wrinkles layer on top of that?
How would you set it up so the wrinkles or skin layers slide over one another without sticking though one another?
For clothing I can understand either using cloth with cloth collisions or just rig it in such a way so that the inner layers don’t stick through the top layers of clothing. I found good You Tube tutorials on how to create layered clothing and I get that.
Working in Blender.