How to redirect using $this-session-userdata(country_territory)

You can't use variables surrounded by single quotes.
Try this:

PHP Code:

redirect('countries/'. $country); 


You'll also need a route, otherwise CI thinks the $country is a function in the countries controller.
By default, the first segment in a url is the controller, the second segment is the function.

Thanks Wouter60, I changed your coding a little and without a route and everything appears to be working good now.

PHP Code:

redirect('/'. $country);