SSRS Multi Select Parameter, both Null and not null

SSRS Multi Select Parameter, both Null and not null

I'm new to SSRS, and have been tasked with a report that allows users to
select NULL, non NULL or both.
For example
Name | ID
BOB 1
ALICE 2
DAVE NULL
ROGER NULL
Users need to be able to select Records with an ID value and/or records
with no ID value. So it would be a multi select parameter (ID, NO ID ,
ALL).
I can make this work with a sql query, but am not sure how to make it work
with user parameters that can be either, or or both.
The id field is a decimal.
Any advice for how to do this?
Thanks.