Welcome to our new Microsoft Q&A Platform.
Hi
There are 3 different configuration support for RDSH and RD Licensing Server to work for CAL
• Both in the same workgroup
• Both in the same domain
• Both in the trusted (Two-way trust) Active Directory Domains or Forest
So if it for multiple domains, you may need to establish domain trust to add session host from domain different than that includes connection borker.
You could also refer to the KB for more details.
Best practices for setting up Remote Desktop Licensing (Terminal Server Licensing) across Active Directory Domains/Forests or Workgroup
https://support.microsoft.com/en-us/help/2473823/best-practices-for-setting-up-remote-desktop-licensing-terminal-server
Thanks