Users are identified uniquely by both their user name and domain. The default experience for users who log in to the Workspace ONE portal from VMware Identity Manager is to select the domain to which they belong on the first login page that displays.
Because users select their domain first, users that have the same user name but in different domains can log in successfully. For example, you can have a user jane in domain eng.example.com and another user jane in domain sales.example.com
VMware Identity Manager displays the authentication page based on the access policy rules configured for that domain.