add componentsseparatedbystring into a predicate with core data

i have a String stored in an Entity (core data) i want to use an NSFetchedResultsController to get data.

string format: abc,ba,x,s,d. this is an array of IDs saved as string.

i want to get only entities that contains at least an IDs in that string.

the problem is if i use CONTAIN in the predicate and search for "a" i will get a wrong result.

could you please tel me if it's possible to add something like "componentsseparatedbystring" in a predicate so i can iterate and use "in"in the result or if there's an other solution, thanks.