qtd calculation in dimensional reporting

[pp050]

hi all i have year and month prompt i want to  calculate qtd ,can any body help me i m using dimensional data

[Bark]

Have you got a quarter level on your time dimension?

[pp050]

No... actually i m not getting how get selected param value in dimensional data if i get that i can calculate qtr  by using lastperiods function  then using aggregate function i can display the qtr wise revenue