Below is the similar solution of your problem -
Following are the tables and data used for report creation-
create table dslocation
(
locationId int
, locationName varchar(20)
, mmpremium int
, sspremium int
)
INSERT INTO dslocation
VALues (1, 'SANDY', 1000,'')
,(2, 'RANSY', 2000,'')
create table prevdslocation
(
plocationId int
, plocationName varchar(20)
, pmmpremium int
, psspremium int
)
INSERT INTO prevdslocation
VALues (1, 'SANDY', 2000,'')
,(2, 'RANSY', 3000,'')
Then add a column and write following expression in placeholder-
=Fields!mmpremium.Value-join(LookupSet(Fields!locationId.Value,Fields!plocationId.Value,Fields!pmmpremium.Value,"prevdslocation"),",")
Following is the screenshot of the solution -
[![enter image description here][1]][1]