How to validate object with form validation [Laravel 5]

I am trying to do validation something like this:

foreach (json_decode($this->request->get('depencies')) as $deps) {
            print_r($deps->id);
            $rules['depencies.' . $deps->id] = "exists:tasks,id,admin_id,$adminId|numeric";
        }

But don't work. Any solution for this?

via Chebli Mohamed