Note: I created this module for a project in which I needed this, but probably I won't need it again so I hope there is someone who can take over maintenance. The code is pretty trivial though, it should keep working as long as the Drupal permissions API doesn't change.
This module consist to create country state field on contents types.
The display of this fields will be a dropdown select lists country/state.
I have created new views filter handler to combine those two sub-fields (country/state) in filter widget.