I have a heat map that currently ranks the client by year.  If they have years in the view, it will rank the years, if it the view is expanded to quarters, then it will keep the year rank and color them accordingly (rank q1 2015 to q1 2016 etc)

I need to keep the same format but create a parameter where the user can select a drop down of Year, Quarter, or Month, and have it perform the same function as the +/- buttons.

I've tried creating a parameter and then using a case with datetrunc which allows me to select yearly or quarterly, but the heat map does not stay in the same format as it does when manually choosing year, quarter, or month.

Is there a way to create a parameter to do this while the ranking calculation stays the same, as it does without the parameter?

Essentially I am trying to keep the worksheet the same, but only use a parameter to select the date granularity (years, quarters, months) so the user doesn't have to find the +/- buttons.

Thanks!