Right click your project, and goto version control, you can create any version. If you need to recover, just recover it , more easier  and more cleaner.

Under version control you have only one version as current/actual. Project group allow keep together multiple version of one or more related projects. By example I have some device in 3 modification - lite, std and pro. Schematic very similar, but have some differences, and PCB also different. Other sample. I have project with 4 modules on different PCB. And last sample - single schematic but different component size. As result two project - SMD and axial version