First, welcome to theSwamp.
If you select an entity, then you will notice that it has a dxf code 330 within the code 102. This is where you can find if it's from a group. If so, then the entity will be ' GROUP '. Within that, all the code 340 seem to be entities within the group, so you could just step through those and find what you want.
If you need more help than that, let us know.