You can switch to a tenant-specific TCA environment and view the details of the tenants available to you based on your role and permissions.
If you are a system administrator, you have access to all the tenants in the system. If you are any other user, you have access to the tenants based on the roles and permissions assigned to you.
When you switch to a tenant-specifc view, you see the resources that the tenant is aware of. For more information, see Sharing and Categorizing a Resource.