How can I identify the first occurrence of a repeating event in Calendar Before Sierra Calendar and after "defaults write com.apple.iCal IncludeDebugMenu 1" we could locate the first event of a repeating event in our calendar. This was extremely useful for deleting all linked events from without having to hunt them down one by one. This would be required if one of the events became disassociated from the rest of the repeating events because a change had been made to it, like time of day.

Has anyone figured out how to replace this removed "feature" - the debug menu?
One out-of-the-box method is to drag the event to the desktop, creating a .ics file. When you have a QuickLook of the .ics file by pressing the space bar, a preview of the recurring event will come up with the event's start date in the title bar.
Works with Big Sur.