(suggestion)
#1. Create alert from oob alert template (monitor all groups in OU), or if not available, something close with alert scope (objects in OU). Review and edit XML body of the alert.
#2. Maybe create ad\my_group and oob alert: monitor all groups (objects) memberOf the ad\my_group?
(suggestion)
#1. Create alert from oob alert template (monitor all groups in OU), or if not available, something close with alert scope (objects in OU). Review and edit XML body of the alert.
#2. Maybe create ad\my_group and oob alert: monitor all groups (objects) memberOf the ad\my_group?