Basic mechanism question

Ok, trying to learn something about mechanisms..

I have two bodies and a ground. here is a simplified image:

I need that body 1 and 2 slide away from ground:

Then I need body 2 to come in reverse direction:

I have to work with subassemblies because I have a lot more components than it is represented in images.

Now what´s the best way to deal with this?

1. Create a assembly for body1 and inside, another subassembly for body2?

2. Create independent assemblies for each? But when I create a motor, I can only choose one connection, and I need them to move simultaneously in first step...

Any help will be apreciated..

Jose