Samba config file syntax

I hope I'm posting in the right forum.

In the samba config file smb.conf in the global settings area... we currently have a domain in the workgroup section as
workgroup = domain_name

I want to add another domain name to allow attaching to samba. What is the syntax to add another domain name? I'm guessing:
workgroup = domain_name anotherdomain_name

Thanks,
Paul

Afaik it is only 1 workgroup name being allowed. At least the documentation sounds like it:
Configuration of the /etc/smb.conf file

Also what hinders you from testing it out?