Sum of columns in pivot table from Power Pivot Data Model|Power Pivot|Excel Forum|My Online Training Hub

Hi all,

I did a pivot table from Power Pivot Data Model (raw file is a flat file) and I'd like to sum some of the columns in the pivot file.

See the attached image.

I'd like to 

-sum the February related columns in a new column "Total Feb'22" and
-sum the March related columns in a new column "Total Mar'22"

I can do this with calculated items in normal pivot table but it is greyed out when I try to do it in a pivot table from power pivot data model.

I'd really appreciate if anyone has a solution to this.

Regards