In your query u'll have these parameters

@ApplicationName = 'Informatica' or 'Velocity' or 'MSCloud' --manually added to parameter

@EnvironmentName = 'PROD' or 'UAT(ITSM = PROD)' --manually added to parameter

and for "@ServerName" parameter u can use this query and add to dataset..

IF OBJECT_ID('TEMPDB..#ServerName','U') IS NOT NULL

DROP TABLE #ServerName

SELECT * INTO #ServerName FROM(

SELECT ServerName = @ApplicationName+@EnvironmentName

)S

SELECT * FROM #ServerName

If you choose ApplicationName = 'MSCloud' and EnvironmentName = 'PROD'

In the servername dropdown it will only show 'MSCloudPROD' .

Hope it will help u a lot.