Display different Categories groups in custom breadcrumbs
I've managed to solve it. &lt;span class='nav-item'&gt;&lt;a href="{{ category.counties.first().url }}"&gt;{{ category.counties.first().title }}&lt;/a&gt;&lt;/span&gt; did the trick.

Clearly I just needed to print the category field, although I'm not sure why it needs the .first() after category.counties to print it? But it works at least after days of struggling to find an answer.