toc.html

<div class="navbar-light navbar-expand-md bs-sidebar hidden-print affix" role="complementary">
    <div class="navbar-header">
        <button type="button" class="navbar-toggler collapsed" data-toggle="collapse" data-target="#toc-collapse" title="Table of Contents">
            <span class="fa fa-angle-down"></span>
        </button>
    </div>

    {% macro toc_item(item) %}
        {%- if item.level <= config.theme.navigation_depth %}
            <li class="nav-item" data-level="{{ item.level }}"><a href="{{ item.url }}" class="nav-link">{{ item.title }}</a>
              <ul class="nav flex-column">
                {%- for child in item.children %}
                    {{- toc_item(child) }}
                {%- endfor %}
              </ul>
            </li>
        {%- endif %}
    {%- endmacro %}
    <div id="toc-collapse" class="navbar-collapse collapse card bg-secondary">
        <title class="text-center d-block container-fluid rc3-block-head">{% if page and page.title and not page.is_homepage %}{{ page.title }}{% endif %}</title>
        <ul class="nav flex-column">
        {%- for item in page.toc %}
            {{ toc_item(item) }}
        {%- endfor %}
        </ul>
    </div>
</div>