I found the group edit tool very difficult with many props that I've created and imported, so I've used a different technique... Each part (or eventual group) that I want to identify, I assign to a different material in my modeling program. That information is carried over in the *.obj file into poser. Then you use the group edit tool to create new groups, but select the polys by the "add material" button. Then you don't have to do all of the selection using Poser's more limited selection options (in group edit).