Need a little direction on CompanyDirectory hierarchies

[turpentyne]

I'm stuck waiting for a plane back to the Southwest, and learnin' me some new stuff.

I've implemented the CompanyDirectory module, and started populating things. I'm putting countries into the hierarchies, and I want to add a dropdown to the page where the user can select a country to automatically narrow results.

I see this: {cd_selhierarchy}

But I'm not sure I understand how I can use this for my needs. It populates a dropdown on the page, but I guess I hoped it would automatically narrow results, but it doesn't seem to do anything. What's the best way to do what I want?