Use NSPredicate
with format of SELF.locationName = 'some location'
on an array of the elements:
NSPredicate * p = [NSPredicate predicateWithFormat:@"SELF.locationName = %@", @"My Location"];
NSArray * filteredArray = [yourArray filteredArrayUsingPredicate:p];
NSDictionary * firstElement = filteredArray[0];