Previously managers, by default, had access to all of the users within an agency. Now, from the admin account, a manager can be assigned to only certain agents.
When you log in as a Manager then you have only those limited Agents/CSR profile that was assigned to you. Visibility, data access, and other features will be routed accordingly.
To view and control the features and access, Admins can switch to Agent and can select the desired agent allotted under them.