SSRS - How to use ##Temptable for data set parameters

Question

I have an SSRS report the has cascading parameters, but the report is experiencing latency issue in loading cascading parameter. Is there a method to use global temptable '##' for each cascading parameters i have.

1. Created a Global Parameters ##Parameters

   DROP TABLE IF EXISTS ##Parameters SELECT * INTO ##Parameters FROM Process.func_ClientListRollUp_RptGroup(@StartDate, @EndDate, 'CSA,BAOB,CAOS,NONE', 'PG')

2. Called a parameter from ##Parameters

SELECT DISTINCT PGType FROM ##Parameters WHERE LOB IN (@LOB) ORDER BY PGType

3. Received an Error upon report rendering

An error has occurred during report processing. (rsProcessingAborted) Query execution failed for dataset 'PGType'. (rsErrorExecutingCommand) Invalid object name '##Parameters'.