How do I report on parent/child test plan relationships?

I have users with a Parent/Child Test Plan relationship in RQM.  They would like to report on this relationship using Rational Insight.  They would like to show the Parent/Child links, or possibly filter out test plans to show only parent test plans or only children test plans, but it's not obvious if this is possible in the data model.

I've tried "Test Plan Related Test Plans" but it doesn't seem to be representing the relationship as I would expect. Is there some other way to do this?