For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.3.
# smbadm add-member -m member-name [[-m member-name] ...] group-name
member-name can be specified as [domain-name\]username or [domain-name/]username. The domain name is the domain in which the user can be authenticated. By default, the domain name is the name of the domain that you joined.
The backslash (\) is a shell special character and must be quoted. For instance, escape the backslash with another backslash: domain\\username. For more information about handling shell special characters, see the man page for your shell.
For example, to add user john of the sales domain to the wsales group, type:
# smbadm add-member -m sales\\john wsales
You add a local user to an SMB group in workgroup mode by specifying the Oracle Solaris user name. For example, to add local user john of the solarsystem host to the wsales group, type:
# smbadm add-member -m john wsales