Hi RUC,
if you are using Oracle data sources then you can add predefined filter with logic as below in the universe and use it in the report query.
Table.Sales_Date between add_months(add_days(last_day(Table.Sales_Date),1),-12) and last_day(Table.Sales_Date)
add_months(add_days(last_day(Table.Sales_Date),1),-12) - Derive at the first day of next month from the given sales date and subtracting 12 months from there.
last_day(Table.Sales_Date) to ensure you are getting data until the last date of the month given by the sales date.
Hope this helps
Thanks
Mallik