how to search on collection attributes

I have a parent object A which owns a collection of child objects of
class B. B has a name attribute. How do I run the query "get me all A
where one or more of the Bs owned by that A has a name attribute equal
to 'Leroy Jenkins'".

I've been looking through the various 1:n documentation sections on
db.apache.org and haven't found anything that I think covers this.

Thanks.