Comparison of a value with the 1st value in each group

[#1]

Customer	Product	Product Sort	Exposure	Exposure change
C1	P1	1	100	0
C1	P2	2	200	100
C1	P3	3	300	200
C1	P4	4	400	300
C2	P1	1	1000	0
C2	P2	2	500	-500
C2	P3	3	2000	1000
C2	P4	4	3000	2000

Hello All, The above is a table in UI . Its hows the customer exposure by Product and the table is sorted based on product sort. I am trying to calculate the last column (Exposure change) in the Chart-Table. Exposure Change is calculated as exposure of the product- exposure of the 1st product within the customer group( P2-P1, P3-P1, P4-P1) within the customer group C1. The same logic applies to customer group C2 and so on.

I tried the sum(Exposure)- Above(Sum(Exposure)) but I couldn't get the above function to get the first row. Also, the above function needs to get the first row within each customer group.   Really appreciate any thoughts or ideas to make this work in UI

Thanks,

Bharath

[sunny_talwar]

May be like this

Sum(Exposure) - Sum(TOTAL <Customer> {<[Product Sort] = {1}>} Exposure)

[sunny_talwar · Accepted solution]

Or this

=Exposure - FirstSortedValue(TOTAL <Customer>Exposure, [Product Sort])

[#4]

Thanks Sunny