The report will be shown like below.
In Reporting Services, by default, the textbox displays”<Select a Value>” text before selecting values in a single parameter drop-down list. But nothing would be shown in the start up of multivalue parameter list. This is by design.
To work around this issue, we can specify the Available Values from the batchId field in the following dataset:
select 'select any value' as batchId
select distinct CAST(batchId AS VARCHAR(1)) from dbo.Table1
Then specify the 'select any value' as the Default Values for the multiple parameter. In this way, we should change the values in the drop-down list when we render the report.