zet.oliverdavies.uk/source/_includes/zets/related.html.twig

{% if related and zets %}
  <section>
    <h2>Related</h2>

    <ul>
      {% for zet in zets if related|filter((title) => title == zet.title) %}
        <li>
          <a href="{{ zet.url|trim('/', 'right') }}">{{ zet.title }}</a>
        </li>
      {% endfor %}
    </ul>
  </section>
{% endif %}