Generating a nested navigation in Jekyll with Liquid

navigation.html

{% assign pages = site.html_pages | where: 'visible', true | where_exp: 'page', 'page.url contains include.context' | group_by: 'dir' %}
<ul>
  {% for group in pages %}
    {% if group.size > 1 and group.name != include.context %}
      <li class="{% if page.url contains group.name %}active{% endif %}">
        <span>{{ group.name | replace: '/', '' | capitalize }}</span>
        {% include navigation.html context=group.name %}
      </li>
    {% else %}
      {% for item in group.items %}
        <li>
          <a href="{{ item.url }}">{{ item.title }}</a>
        </li>
      {% endfor %}
    {% endif %}
  {% endfor %}
</ul>

hi fred,
I am following your code to get a dropdown in my project page ,but it is not working. can you help on understanding these lines ?
{% if group.size > 1 and group.name != include.context %}<li class="{% if page.url contains group.name %}active{% endif %}"><span>{{ group.name | replace: '/', '' | capitalize }}</span>{% include navigation.html context=group.name %}</li>

Hello, Fred!
Same here, could you please help us with a quick overview of your code?
Thanks!

It works without "group.size > 1 and"