Disable Force being transferred between 2 collision groups

[dekarguy]

I am trying to set up a simulation with 2 collision groups

Boxes - Can collide with Players and Boxes, and transfer force to either
Players - Can collide with Players and Boxes, but can only transfer force to Players

Otherwise, I want a Box to act as a static shape and repel the players if they run into them, but be non-static if another Box runs into them (or gravity)