Predicate to return list of objects whose children contain objects with a specific name

Predicate to return list of objects whose children contain objects with a
specific name

For example get me the list of all Parents that have Children named "david".
I have a class Person with the following attributes:
NSString *name
NSSet *children (of Persons)
I want to do something like this:
@"children.names contains[cd] $value"
Any idea on whether this is possible in IB and if so what would the
predicate string look like .
If not then what other options are there for filtering a list in this manner.