Filter Multidimensional Array?

FROM : Chris Purcell
DATE : Sat May 17 03:40:07 2008

I have created a multidimensional array by creating 3 NSArray's (call 
them childArray1, childArray2, childArray3) and them adding them to 
one NSArray (call it parentArray).  I am using predicate to search out 
the array which finds the item I'm searching for.  However, how I 
return the name of the original array that the found item came from 
(either childArray1, childArray2 or childArray3)?