You can use OnCommand API Services to retrieve this information. When deployed in environments with OCUM, API Services gives you access to events triggered by UM.
If you notice in the screenshot attached, you can either filter by timestamp (use the UNIX timestamp) and/or source resource key (a unique key assigned to the storage object that acts as your source of the event)
The API call will look similar to
This will give a consolidated list of all the events triggered from UM by the same source at the same time.
Thanks and Regards,