I have parts in a sub-assembly. That sub-assembly is located in another sub-assembly. The parts are currently fixed, and I want to float them and then add some mates.

I do not get the option to float the parts after a RMB selection. Both of the sub-assemblies above these parts are not fixed. I can drag the subassembly around and move it as a group.

Am I being stupid? Any ideas?

Thank you.