CURRENT YEAR SALES DATE PARAMATER AND PRIOR YEAR SAME DATE RANGE

I am pulling data from a SQL view dbo.view that has current and historical SOP data by line. The date paramater is a date range, uppr date and lower date formulas are in the report. I need to include prior year SOP data for the same prior year date range in the detail. I have tried adding the view in twice with no luck, just duplications. Ultimately I want to supress the detail and only show the totals by customer so it is comparitive. Thanks for your help. Jayne