At present, if you want to send a notification to the managers of a resolver group, you have the action macro 'Notify Group Manager' (for request/incident/problem) which is not really satisfactory. It would be better if group managers could be notified with a multiple notification macro because that would use a template.
Suggested way forward
Add a new column 'managers' to the contact table, intended for use only when the contact type is 'group'. It would be a QREL returning contact records which are members of that group with the 'manager' flag set (and perhaps also the 'notify' flag).
You would then create an Object Contact Notification which uses this new column, and use it as an object contact in notifications.