Currently, there is no way to create a subscription for change notifications that track changes to all /groups WITHOUT group membership changes. I know this functionality is available using delta queries with the $select parameter, but that is a pull operation rather than the automatic push notification that is available via webhook notifications/subscriptions. Having this functionality can cut down on the number of notification messages received for groups where membership changes are NOT desired or wish to be tracked by this method - for which in that case, delta notifications could be substituted for that purpose as previously indicated.
Please advise. Thank you!