The Rules and Filters panel is the only user interface component available to Designers and not to Developers. It is a very powerful tool.
Rules and Filter is a panel window within
The window is a shortcut bar, you can choose to display the Rules part or Filters part.
You can choose which part of the meta-model is displayed by clicking on Rules or Filters titles in the shortcut bar. Within these two sections, you can respectively define the rules and filters your the meta-model.