Panel Permission: Editor only see his own Pages

Hellooo - I try to get into permissions. I want it that the editor only sees his own Pages.
How it looks:

How I want it:

What I tried in the editor.php:

  ''     => function() {

  if($this->user()->is($this->target()->user())) {
    return true;

But it does not work…

How do you know what pages a user may see? Is there any pattern, like a template, a field or whatever which determines what a user may or may not see?