no PriorYear_Period and PriorYear_YearToDate measure in datasource

[jj22171]

I'm working on a financial report with current period, year-to-date columns and comparative columns for same period and year-to-date from prior year. Datasource is a cube but unfortunately, it doesn't have the PriorYear_Period and PriorYear_YearToDate as measures. Cube has FiscalYear dimension with Year (eg. FY2012) and Period (eg. 201205-Sep11).Dataset is filtered by period using a parameter. I can have two datasets, one for each FY and a sub-report for prior year but it means, I need to create a separate parameter for prior year. Is there a better approach, like having one dataset with prior year comparatives?

Thanks a lot for whatever tips/suggestions.