I am using CLM suite 6.0.3.

I was wondering how to query based on an attribute that is of type "work item". The attribute allows for the singular selection of a work item in the repository. I want to create a query which finds all work items that have this attribute unassigned. I currently only see a means to query based on the selection of a specific work item, not whether a work item has been selected or not. Is this possible? Any help would be greatly appreciated.