Jetson Mate Cluster

Is the 4xUSB3.0 ports on the Jetson Mate Cluster Board each routed to a slot for Xavier NX? Or is all 4 USB3.0 routed to the master node?
For example, is the master USB3.0 (as shown in the wiki: https://wiki.seeedstudio.com/Jetson-Mate/)
linked to the master node slot?

The reason I ask is that I would like to connect 1 USB3.0 camera (total 4 cameras) to each of the nodes (Xavier NX).