Utilizing multiple field selections in pivot table

[kgwen100]

Hi all,

I currently have a pivot table with customer names as my row, regions and year as my column and revenue as my measure. My current formula is such:

    Sum({$<[Waterfall $(=GetFieldSelections(Year))] = {'Renewal'}>}Revenue)

Where I am filtering on renewals for a current year. e.g. if i only select 2019 I get 

    Sum({$<[Waterfall 2019] = {'Renewal'}>}Revenue)

My current issue is if the user selects multiple years, then my formula breaks, because my formula reads

    Sum({$<[Waterfall 2019, 2020] = {'Renewal'}>}Revenue)

Is there a way to limit my formula to the years selected? Such that 2019 would be Sum({$<[Waterfall 2019] = {'Renewal'}>}Revenue) and Sum({$<[Waterfall 2020] = {'Renewal'}>}Revenue)