Functions in EPRCS

Content

Hi,

We need last period of prior quarter to be shown in the management report. Current period is in "CurrentPOV"

Eg :

If Dec-20 ,Nov-20, Oct-20 is in POV, then it should show Sep-20
If Sep-20,Aug-20,Jul-20, then it should show Jun-20.

Appreciate any help with the functions/logic for this.

Thanks!