Overview
Add a second template in the Templates pane to create a set from the open project.
The Templates pane
The Templates pane switches the canvas between set members.
Shared controls and asset slots
Expand Shared controls and asset slots in Scene Outliner to define parent controls and shared assets.
Master Brand Kit
Open Brand Kit, then choose Use this Brand Kit for set to adopt the active template's tokens as the set-wide master.
Live components
Select objects and choose Resources → Components → + Create Component.