Previous Custom Fiscal Period Column in Date Table

Hello, I have been working with custom fiscal weeks and periods. a Fiscal period is 4 weeks - There are 13 fiscal periods in a year. I have a DimDate table that has the typical date, year, month, day, week in year, FiscalWeek, FiscalPeriod, IsCurrentFiscalPeriod (True/False), FiscalPeriodStartDate.

I am looking for a way to filter a visual for the previous fiscal period based on the current fiscal period. Something like:

PreviousFiscalPeriod = DateAdd Current Fiscal Period -1 Fiscal Period.

Thanks