How do I return description to XFBR from a multiselect prompt?

We are using the multiselect tool to gather certain entities for reporting, which will show up in rows in a cube view. We're returning to the cube view the values from the multiselect via an XFBR. When the user chooses the entities, we can't get the resulting members in rows to show as description, only as member name. Anyone know how to return the description in a cube view/report?