Pass path parameters automatically

I'm building a site where the user can choose a country, state and city he wants.

Once he selects these parameters he goes to a page like this: en.example.com/spain/madrid/madrid/

The problem is, every time I want to build a new url, I must pass these 3 variables and I was wondering if I could do something to make them just like the _locale variable which symfony itself passes it to the parameters.

Thanks

After searching more I found this post: http://blog.viison.com/post/15619033835/symfony2-twig-extension-switch-locale-current-route

I just used the idea and made the changes I needed and this is the final code for my extension

<?php

namespace Comehoy\CoreBundle\Twig\Extension;

use Symfony\Bundle\FrameworkBundle\Routing\Router;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\HttpKernel;

class PathExtension extends \Twig_Extension
{

    private $request;
    private $router;

    public function __construct(Router $router) {
        $this->router = $router;
    }

    public function onKernelRequest(GetResponseEvent $event) {
        if ($event->getRequestType() === HttpKernel::MASTER_REQUEST) {
            $this->request = $event->getRequest();
        }
    }

    public function getFunctions()
    {
        return array(
            'l10n_path' => new \Twig_Function_Method($this, 'getPath')
        );
    }

    public function getPath($name, $parameters = array())
    {
        $parameters = array_merge($parameters, [
            'country' => $this->request->get('country'),
            'state' => $this->request->get('state'),
            'city' => $this->request->get('city'),
        ]);

        return $this->generator->generate($name, $parameters, false);
    }

    public function getName()
    {
        return 'twig_my_path_extension';
    }

}

And as for the configuration its the same as the post

services:
    twig.localized_route_extension:
        class: Acme\CoreBundle\Twig\PathExtension
        tags:
            - { name: twig.extension }
            - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }
        arguments: [@router]

And for the routes that I use country, state and the city I put them in the prefix to avoid repeating them in each route.

acme_core:
    resource: "@AcmeCoreBundle/Controller/"
    type:     annotation
    prefix:   /{country}/{state}/{city} 

Hope it helps someone else.