Creating Restricted-User Logins

Request

It would ne nice to create different restricted-user logins, for Client accounts, depending on rules set by the Client's main user (also called administrator). In that way: - Some user-login will have access to Billing or Purchase a Product, for example Client's Finance team; - Some other user-login, like Client's technical support, WILL NOT have access to the above, but will JUST have access to "My Services", and/or "My Domains", with even the option to segregate those rights.