You could use the parseDateTime function https://docs.mendix.com/refguide/parse-and-format-date-function-calls/ to get the month value parseDateTime([%CurrentDateTime%], ‘MM’) and then use a decision to create the quarterly. So if the value is 01,02 or 03 it is Q1 etc. You could do the same to get the year value and then create your quarterly string.
Regards,
Ronald