Display Associated Top-Level Category Links on Sub-Level Categories

We're trying to customize our categories so that when you view a sub-category, you'll also see a list of top-level categories the sub-category belongs to.

The code we're currently using is:

{foreach from=$categories item="category" name="categories"}
| {$category.category}

But 1) it doesn't seem to be showing these categories

and also 2) I thought of using Bread Crumbs, as that's essentially what we want (minus the 'Home' link at the top), but also including the other Top-Level categories.

Thirdly, 3) We're considering having these categories broken down by Feature, so other categories that contain product with a particular feature will be shown in this list.