[A, A->B, A->C] => {A & B} & {A & C}

gistfile1.h

	NSManagedObject *itemA = [NSEntityDescription insertNewObjectForEntityForName:@"Group" inManagedObjectContext:self.managedObjectContext];
	NSManagedObject *itemB = [NSEntityDescription insertNewObjectForEntityForName:@"Subgroup" inManagedObjectContext:self.managedObjectContext];
	NSManagedObject *itemC = [NSEntityDescription insertNewObjectForEntityForName:@"Folder" inManagedObjectContext:self.managedObjectContext];
	
	NSFetchRequest *aAndBFetch = [[NSFetchRequest alloc] initWithEntityName:@"Group"];
	NSFetchRequest *aAndCFetch = [[NSFetchRequest alloc] initWithEntityName:@"Group"];
	
	[aAndBFetch setIncludesSubentities:YES];
	[aAndCFetch setIncludesSubentities:YES];
	[aAndBFetch setPredicate:[NSPredicate predicateWithFormat:@"entity.name == \"Group\" OR entity.name == \"Subgroup\""]];
	[aAndCFetch setPredicate:[NSPredicate predicateWithFormat:@"entity.name == \"Group\" OR entity.name == \"Folder\""]];
	
	
	NSArray *aAndB = [self.managedObjectContext executeFetchRequest:aAndBFetch error:nil];
	NSArray *aAndC = [self.managedObjectContext executeFetchRequest:aAndCFetch error:nil];
	
	NSLog(@"aAndB: %@", aAndB);
	NSLog(@"aAndC: %@", aAndC);