All CalDigit Thunderbolt Docks that have more than one Thunderbolt port can support Thunderbolt networking. That means you can use IP over Thunderbolt to connect two computers together.
However, Thunderbolt networking can only support 2x computers. Device such as Element hub has 4x Thunderbolt ports, but you could only use the [Computer] port to connect one computer as a host, and one of the downstream Thunderbolt ports to the second computer. If you add the 3rd computer to Element hub, the entire Thunderbolt networking will be brought down.
Also unlike the regular Cat5/6 Ethernet cable, the length of Thunderbolt cable is limited – up to 2-meters, so the best you can have is up to 4 meters from one computer to another through CalDigit Thunderbolt dock.
Windows platform also supports Thunderbolt networking. Please update to the latest Windows version.
For more information, please visit Apple support article: Use IP over Thunderbolt to connect Mac computers