Including 2 segments in a Custom Taxonomy slug

Hi all,

Little bit of an unusual query, and I’ve searched around for a way to do this, but I’ve hit a blank so far.

I have a new site with multiple custom post types, and each CPT has multiple custom taxonomies applied to it. No custom taxonomy applies to more than one post type, and they are mainly used to create a kind of tagging system in which tags don’t share between post types.

ATM, I have this URL structure (as an example)

/portfolio/{slug}
/skills/{skill_taxonomy_slug}

But, I really need (for sake of hierarchical URL structure to create a structure like this:

/portfolio/skills/{skill_taxonomy_slug}

It’s my understanding that I could do this using WP_Rewrite, but I’m not too familiar with this, and so far, trying to use add_rewrite_rule hasn’t been too successful. The docs on Codex.www.ads-software.com are still a bit sparse, and disagree with each other on how to do things, and the tutorials elsewhere on the web are all focused on how to do this top add endpoints, rather than ‘move’ stuff around like this.

I think I may have to remove some rules, and replace them, rather than just add some, but I’m not sure.

Any and all help gratefully received.