Set analysis is operating on the sets defined by your field values. So, without knowing the fields, their data and their relation, it's hard to give a specific advice for non-trivial cases.
In your case, it seems you are using a fiscal master calendar.
I assume your master calendar also shows calendar month next to fiscal month.
So it's not 100% clear to me if Month, MonthOrder and Qtr are referring to which calendar system.
It's also not clear if your calendar is showing all dates for current (fiscal) year or only dates up to today (ToDate). And if you are looking for the max possible month in quarter 2 or the max defined by the calendar logic (i.e. a non existing month in your data set if you are using a ToDate creation of your calendar).
This may all sound a little complicated and confusing to you, but not more than your request may look to us.
tldr: Please post some sample records to show how your calendar looks like and your requested result.