Custom Post Type and Taxonomies

I hope someone here can help me with a bit of a problem.

I am working on a WP site where I have created a Custom Post Type called Retailer.

In there I have Country, Region and City

Now I want to filter these taxonomies based upon 1. Country - Ex. Denmark 2. Region - if Denmark is chosen in country show Regions in Denmark 3. City - And when Country and Region is chosen show the cities of the Region.

Hope someone can point me in a direction on how to achive this.