How to create in a module a quarter option?



I have a forecast module, with monthly TimeScale and I want to create, in this module, an option for a quarterly view. So basicly, if the client wants to see the data quarterly, he should be able.

I also have a MOD02 Quarter Time Settings and also a filter module for the quarter part.

At this moment, my data is being taken from other modules and each line has a lookup formula. Example :

Forecast = ModelA.Data[LOOKUP: ' MOD01 Lookups Seetings.Forecast, Lookup:' MOD01 Lookups Seetings.AMOUNT].

Is there a way to make this formula optional for quarter view? Client should be able to choose from the UX page the year, the Quarter (if he wants) and then the month. AT this moment, he is able to choose only year and month.