grouped

{% grouped article_groups by page in site.latest_articles %}
  {% for article_group in article_groups %}
    {{ article_group.page.title }}
    {% for article in article_group.articles %}
      {{ article.title }}<br/>
    {% endfor %}
  {% endfor %}
{% endgrouped %}

{% grouped element_groups by region in elements %}
  {% for group in element_groups %}
    {% for element in group %}
      {{ element.title }}
    {% endfor %}
  {% endfor %}
{% endgrouped %}