iPad Multiple predicates in various tableviews

I just can´t stop searching and reading about the "changing of the predicates" but i still don´t know how to resolve my problem, so...what i have is:

1 - Several tableviews with various cells and each cell has multiple textfields.

2 - The user presses one of these textfields and a tableview(inside a popover) appears.

3 - this popoverTableview has all the core data "work" and it is suppose to provide data to insert in the pressed textfields.

4 - Everything works fine...EXCEPT the fact that i need the predicate to change every time the user passes for example from tableview1 to tableview2.

5 - Below is my NSFetchedResultsController method that is inside my popoverTableview and i have tried numerous approaches like: "if´s" ; "switches" ; also point to the textfield tag in the tableviews and nothing. I think i don´t need to set the cache to nil since it is already set to nil...also tried deleting the: if (_fetchedResultsController != nil) return _fetchedResultsController;

And nothing!!!, what do i need to understand? What i´m not getting? i´m losing days on this one.HELP!

- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController != nil)
{
return _fetchedResultsController;
}

NSFetchRequest *fetchRequestList = [[NSFetchRequest alloc] init];
NSEntityDescription *entityList = [NSEntityDescription entityForName"List" inManagedObjectContext:self.managedObjectContext];
[fetchRequestLista setEntity:entityList];

TableViewOne *table1 = [[Cobertura alloc]init];
TableViewTwo *table2 = [[Cobertura alloc]init];

if (table1 textFieldShouldBeginEditing:table1.textFieldPressed)
{
fetchRequestList.predicate = [NSPredicate predicateWithFormat"%K IN %@", @"reference", arrayTableview1];
}

if (table2 textFieldShouldBeginEditing:table2.textFieldPressed)
{
fetchRequestList.predicate = [NSPredicate predicateWithFormat"%K IN %@", @"reference", arrayTableview2];
}

NSSortDescriptor *cellTitle = [[NSSortDescriptor alloc] initWithKey"reference" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:cellTitle, nil];
[fetchRequestLista setSortDescriptors:sortDescriptors];

_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequestLista managedObjectContext:self.managedObjectContext sectionNameKeyPath"referencia" cacheName:nil];
_fetchedResultsController.delegate = self;
self.fetchedResultsController = _fetchedResultsController;

return _fetchedResultsController;
}

Thanks in advance