In IDM 14.2 a Policy xpress data source is unable to return multiple attributes as defined in the documentation.
https://techdocs.broadcom.com/content/broadcom/techdocs/us/en/ca-enterprise-software/layer7-identity-and-access-management/identity-manager/14-2/administrating/policy-xpress/create-a-policy/data-elements.html
Release : 14.2
Component : IdentityMinder(Identity Manager)
This issue has been fixed in IDM 14.2 CP4. (DE386284)
The recommendation is to upgrade to CP5 since it is the latest release.