A few years a go, I vaguely remember having an assembly of parts where I wanted to make a few of the parts a seperate subassembly without having to put it back together. There was a feature or command I used to do that and cannot seem to find it now
Go to Solution.
You want the Transfer command. Type Transfer into the command finder at the bottom of the screen and it will locate it for you.
You select the parts and then select the Transfer command. You can move them to another location in the model or create a new sub-assembly.