$scope.grandParent: {"identity":"gp"}
$scope.parents: [ {"identity":"p1"} {"identity":"p2"}]
{"identity":"p1"}
{"identity":"p2"}
$scope.childrenA: [ {"identity":"ca1"} {"identity":"ca2"} {"identity":"ca3"}]
{"identity":"ca1"}
{"identity":"ca2"}
{"identity":"ca3"}
$scope.childrenB: [ {"identity":"cb1"} {"identity":"cb2"}]
{"identity":"cb1"}
{"identity":"cb2"}