Dynamics GP - SSRS vlookup equivalent to another dataset to get related values

https://www.sqlservercentral.com/articles/using-lookup-function-to-bridge-datasets-in-report-builder

1. We are trying to add the Item UofM to the HITB report
2. Create dataset with lookup values (Eg. ItemMaster)
3. In field, create expression as follows

=Lookup(HITBItemNumber,HITBItemNumber,ItemMasterBaseUofM, LookupDatasetName)

Example:

=Lookup(Fields!ITEMNMBR.Value,Fields!ITEMNMBR.Value,Fields!BASEUOFM.Value, "ItemMaster")