SQL report - Chart filter expression

I have a chart in an existing SCCM report that I want filter down to two or more collections, but the dataset is used in other charts on the same report, so I can't touch that.

I've been trying to create a filter in the Chart Properties, and can limit it down to one collection without issue:

Expression: [CollectionID]
Operator: =
Value: VI100016      (the collection that I am filtering on)

I've tried to go into the Value fx and set an expression manually, example below, but this errors when I run the report.
=(Fields!CollectionID.Value  = VI100016) Or (Fields!CollectionID.Value  = VI100017)