How to calculate intersection customers amt?

[#1]

Hi guys,

I have a fact table as follow:

storeid	customerid	amt
store1	customer1	100
store2	customer2	50
store3	customer3	70
store4	customer1	60
store5	customer3	130
store6	customer4	80
store7	customer5	90

The store 1-3 belong to group A and the store 4-7 belong to group B.

I want to calculate the amt of which customer bought from both group A & B.

in this case means to calculate the amt of customer1 and customer3,

what expression should be used?

[tresesco · Accepted solution]

May be using p() like in the attachment. PFA.

[#3]

Thank you very much,it works!