Getting last completed eight quarters

[cognos05]

Hi I have a dimensional cube with a time hierarchy like belwo without quarters on the levels.

Business doesnt want quarters tobe shown , but i need it for a specif report where i should show the sales by last 8 completed quarters.

My time hierarchy is jul-jun fiscal year

2020
jul 2019
aug 2019
......
jun 2020


so say this month is may and last completed quarter is jan 2020 to mar 2020 .

So I need to get this last 8 quarter months ,

what approach would be better to have this query dynamically every month .

Thanks ,