Can a UriMapping have dynamic subnavigation Uri?

Question

Current navigation Home > categories > subcategories

I have a single page for categories and subcategories that are dynamically filled based on selection. So I have CategoriesHome.xaml and SubCategoriesHome.xaml that I want to base their content on the URI fragment. So basically a user goes to .html#SomeCategory or .html#/SomeOther will end up on CategoriesHome.xaml. This part I have working fine. But when I try to make SubCategories work like so: .html#/SomeCategory/SomeSub it only shows CategoriesHome.xaml. Any way to get the UriMapper to recognize subcategories? Thanks for any help you can give.

<uriMapper:UriMapper
    x:Key="MainUriMapping">
    <uriMapper:UriMapping
        Uri=""
        MappedUri="/Views/Home.xaml" />
    <uriMapper:UriMapping
        Uri="{}{CategoryPageName}"
        MappedUri="/Views/Categories/CategoriesHome.xaml" />
    <uriMapper:UriMapping
        Uri="{}{CategoryPageName}/{SubCategoryPageName}"
        MappedUri="/Views/SubCategories/SubCategoriesHome.xaml" />
</uriMapper:UriMapper>