grav/themes/quark/templates/partials/taxonomylist.html.twig

{% if page.url == base_url ~ "/events" %}
  {% set taxlist = children_only is defined ? taxonomylist.getChildPagesTags() : taxonomylist.get()|filter(page => page.header.event.start is defined) %}
{% else %}
  {% set taxlist = children_only is defined ? taxonomylist.getChildPagesTags() : taxonomylist.get() %}
{% endif %}

{% if taxlist %}
<span class="tags">
    {% for tax,value in taxlist[taxonomy] %}
        {% set label_class = uri.param(taxonomy) == tax ? 'label-primary' : 'label-secondary' %}
        <a class="label label-rounded {{ label_class }}" href="{{ base_url }}/{{ taxonomy }}{{ config.system.param_sep }}{{ tax }}">{{ tax }}</a>
    {% endfor %}
</span>
{% endif %}