If you want to allow other BQE CORE users to access the CORE account details such as the Manage Subscriptions screen, you can do that by setting their role or user type to Administrator in the Manage Users > User Details screen or even from the list view in the Manage Users screen (Settings > Access & Permissions). Note that you must be the CORE owner or administrator to be able to do this. Check CORE Help Center for details.
CORE Help Center