Hi Thotoyame,
Currently "multiple single values" feature is not available in Input parameters. But if you are looking for RANGE of values with START VALUE and END VALUE of the RANGE then you can define two input parameters and use BETWEEN operator in the SQL script.
In case of multiple single values, you can either use dynamic SQL (using EXEC sql) or you can also pass these values to the where clause in your front end reporting.
In most of the cases the WHERE clause filter is also pushed down and can provide you the similar (if not exact same) performance as defining the filters using Input parameters.
Regards,
Ravi