Use wp_basename() to set $terms value in parse_request hook.

[markoheijnen]

This fixes let urls as /en/category/parent/child/ work. $terms should get the value of child and not parent/child. This is also how WordPress internally does it.

[johnbillion]

Marko, can you let me know what this fixes? I can see some issues with parent/child terms but I'm not sure which this is fixing. Thanks!

[markoheijnen]

This fixes the term pages. Only terms without a parent work.

So $wp->query_vars[ 'category_name' ] would be parent/child but you need to pass child to the variable $terms