website/layouts/_partials/grouped.html

{{/* section pages grouped by .Params.group; "cards" shows thumbnails */}}
{{ range .pages.GroupByParam "group" }}
<h2>{{ .Key }}</h2>
{{ if $.cards }}
<div class="thumbs">
  {{ range .Pages.ByTitle }}
  <a href="{{ .RelPermalink }}">{{ with .Params.image }}<img src="{{ . }}" alt="" loading="lazy">{{ end }}<span>{{ .Title }}</span></a>
  {{ end }}
</div>
{{ else }}
<ul class="links">
  {{ range .Pages.ByTitle }}<li><a href="{{ .RelPermalink }}">{{ .Title }}</a></li>{{ end }}
</ul>
{{ end }}
{{ end }}