docker-docs/docs/theme/mkdocs/breadcrumbs.html

<ol class="breadcrumb">
  <li><a href="{{ homepage_url }}"><span class="glyphicon glyphicon-home"></span></a></li>
  {% for section in nav %}
    {% if section.active %}
      {% if section.children %}
        {% for page in section.children[:1] %}
        <li><a href="{{ page.url }}">{{ section.title }}</a></li>
        {% endfor %}
      {% endif %}
      {% if section.children %}
      <li class="active"><a href="{{ current_page.url }}">{{ current_page.title }}</a></li>
      {% endif %}
    {% endif %}
  {% endfor %}
</ol>