How use aggregate formula form two table or use IF in Pivot view

How use aggregate formula form two table or use IF in Pivot view

I want use in aggregate formula from 2 table

But I have this info 

Modified formula can be associated only to the table "Otwarte z filtrem - Support" and not to the existing table "Agents (Zoho Desk)".

Changing associated table is not allowed when editing a formula.

I have 2 table x and y 

In aggregate formula i want create :

(((Table2.y  / "sum table2.y") *100)/Table1.x) *100

Number in table1.x is dependent on "Owner Ticket "

I also have in table 2 "owner ticket" but if i want use 

(((Table2.y  / "sum table2.y") *100)/(if owner is xyz =20,10)) *100

i Have this  

Mixing of Aggregate functions (like SUM, MAX, ...) with non aggregate columns is not allowed.