bootstrap-table/site/_includes/docs-sidebar.html

<form class="bd-search d-flex align-items-center">
  <input type="search" class="form-control"
    id="search-input" placeholder="Search..."
    aria-label="Search for..." autocomplete="off">
  <button class="btn btn-link bd-search-docs-toggle d-md-none p-0 ml-3"
    type="button" data-toggle="collapse" data-target="#bd-docs-nav"
    aria-controls="bd-docs-nav" aria-expanded="false"
    aria-label="Toggle docs navigation">
    {%- include icons/menu.svg width="30" height="30" -%}
  </button>
</form>

<nav class="collapse bd-links" id="bd-docs-nav">
  {%- assign page_slug = page.url | split: '/' | last -%}
  {%- for group in site.data.nav -%}
  {%- assign link = group.pages | first -%}
  {%- assign link_slug = link.title | slugify -%}
  {%- assign group_slug = group.title | slugify -%}
  {%- assign active = nil -%}

  {%- if page.group == group_slug -%}
    {%- assign active = 'active' -%}
  {%- endif -%}

  <div class="bd-toc-item{% unless active == nil %} {{ active }}{% endunless %}">
    <a class="bd-toc-link" href="{{ site.baseurl }}/docs/{{ group_slug }}/{{ link_slug }}{% if link_slug %}/{% endif %}">
      {{ group.title }}
    </a>

    <ul class="nav bd-sidenav">
      {%- for doc in group.pages -%}
        {%- assign doc_slug = doc.title | slugify -%}
        {%- assign active = nil -%}

        {%- if page.group == group_slug and page_slug == doc_slug -%}
          {%- assign active = 'active bd-sidenav-active' -%}
        {%- endif -%}

        <li{% unless active == nil %} class="{{ active }}"{% endunless %}>
          <a href="{{ site.baseurl }}/docs/{{ group_slug }}/{{ doc_slug }}/">
            {{ doc.title }}
          </a>
        </li>
      {%- endfor -%}
    </ul>
  </div>
  {%- endfor -%}
</nav>