title: NSPredicate for array of dictionary that contains an inner array
body: <p>I have the following dictionary</p>
  
  <pre><code>(
  {
      "_id" = 100;
      status = 0;
      student =     {
          "__v" = 0;
          "_id" = 565b5fb94e8e3b72793407c0;
          age = 9;
          parentDetail =         (
              myson,
              mywifesson
          );
     };
  },
  {
      "_id" = 101;
      status = 0;
      student =     {
          "__v" = 0;
          "_id" = 565dfc094afc74bb5a006491;
          age = 9;
          parentDetail =         (
              mywifesson
          );
     };
  },
  {
      "_id" = 102;
      status = 0;
      student =     {
          "__v" = 0;
          "_id" = 565e000f4afc74bb5a006493;
          age = 9;
          parentDetail =         (
              myson
          );
  
      };
  }
  ) 
  </code></pre>
  
  <p>I want filter items with the inner parentdetails contains the string "myson". I tried the following predicate but I am getting all the 3 elements in the filtered array. But actually it should contain only first and last element but not the second element</p>
  
  <pre><code>parentid = @"myson"
  
  [NSPredicate predicateWithFormat:@"ANY student.parentDetail CONTAINS[c] %@", parentid];
  </code></pre>