Jekyll Subnavigation / Subpages (nested)

subnav.liquid

---
layout: default
title: Portfolio
listed: true
---
{% assign entries = site.pages | sort: "path" %}

<!-- We'll split the url and check if the first element is the title of the page, then show it. -->
<ul>
{% for entry in entries %}
  {% assign slug = entry.url | split: "/" %}
  {% assign parentSlug = page.title | slugify %}

  {% if slug[1] contains parentSlug and slug[2]  %}
    <li>
        <a href="{{ site.baseurl }}{{ entry.url }}">{{ entry.title }}</a>
    </li>
  {% endif %}
{% endfor %}
</ul>