QuickTax/docs/_includes/sidebar.html

<div id="td-sidebar-menu" class="td-sidebar__inner">
  
  <form class="td-sidebar__search d-flex align-items-center">
    <input type="search" class="form-control td-search-input" placeholder="&#xf002 Search this site…" aria-label="Search this site…" autocomplete="off">
      <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-docs-nav" aria-expanded="false" aria-label="Toggle section navigation">
      </button>
  </form>  
  
  <nav class="collapse td-sidebar-nav pt-2 pl-4" id="td-section-nav">
    {% for section in site.data.toc %}
      <ul class="td-sidebar-nav__section pr-md-3">
        {% capture sectionUrl %} 
          {{ section.url | replace: "/", "" }} 
        {% endcapture %}
        {% capture pageUrl %} 
          {{ page.url | replace: "/", "" }} 
        {% endcapture %}
        
        <li class="td-sidebar-nav__section-title">
          <a  href="{% if section.url %}{{ site.baseurl }}/{{ section.url }}{% else %}{{ section.external_url }}{% endif %}" class="align-left pl-0 pr-2 active td-sidebar-link td-sidebar-link__section">{{ section.title }}</a>
        </li>
        {% if section.links %}
          <ul>
            <li class="collapse show" id="{{ section.title | slugify }}">
              <ul class="td-sidebar-nav__section pr-md-3">
                {% for entry in section.links %}
                  <li class="td-sidebar-nav__section-title">
                    <a href="{% if entry.url %}
                                {{ site.baseurl }}/{{ entry.url }}
                             {% else %}
                                {{ entry.external_url }}
                             {% endif %}" 
                       class="align-left pl-0 pr-2 td-sidebar-link td-sidebar-link__section">{{ entry.title }}
                    </a>
                  </li>
                  {% if page.url contains entry.url or pageUrl == sectionUrl %}
                    <ul>
                      <li class="collapse show" id="{{ child.title | slugify }}">
                        {% if entry.children %}
                          {% for child in entry.children %}
                            <a class="td-sidebar-link td-sidebar-link__page " id="m-{{ section.title | slugify }}-{{ entry.title | slugify }}-{{ child.title | slugify }}" href="{% if child.url %}{{ site.baseurl }}/{{ child.url }}{% else %}{{ child.external_url }}{% endif %}">{{ child.title }}</a>{% endfor %}
                        {% endif %}
                      </li>
                    </ul>
                  {% endif %}
                {% endfor %}
              </ul>
            </li>
          </ul>
        {% endif %}
      </ul>
    {% endfor %}
  </nav>
</div>