While your project is open in Motion click on File, Open Template. Select your template. In the Project Pane or Timeline select all of the groups. Hit Command and C to copy them. Close out, minimize or move the Canvas to show your original canvas. Paste the groups in your original Project Pane or Timeline. Move the groups around to work with your project and you have a template at the start of what you’re currently working on.
Instead of copying and pasting you can select the groups and drag them over to your other Project Pane or Timeline. This is much easier if you have two monitors. Hope this helps.