Rather than calling this operation to be called repeatedly for each selected value just make all the selected values concatenated into single string and make a single call to database with that string parameter.
Then to get values separating and fetching the result by those parameter will be done by stored procedure.
Ex :-
You can do like
|~|Customer1|#|StartDate1|#|EndDate1|~|Customer2|#|StartDate2|#|EndDate2|~|
and in procedure you can split it by '|~|' and '|#|' strings to get your desired values to use for filtering data.
Here you can see two sets of data can be sent in one go.