Analytics- Attendance date, by recurrence pattern (e.g. every third Sunday of the month)

Hi all, 

I'd like to find an easy way in Analytics to be able to view every third Sunday of the month's numbers, compared to other Sundays. I know I can do this using Day of Week Sort to select only Sundays, and then Days in Date and tick all the specific Sunday dates, but that relies on me remembering to go in and tick the new date every week after the date has occurred (as you can't select future dates with that filter). 

I'm sure I found a way to do something similar to this in a prior organisation, but can't figure it out. Does anyone know if there's a filter for this or have found a good solution? 

Thanks!

Alison