">
        <a class="navbar-brand" href="#">Navbar</a>
      </div>

      <form class="navbar-form navbar-left" role="search">
        <div class="form-group">
          <select class="form-select" multiple data-live-search="true" data-live-search-placeholder="Search" data-actions-box="true">
            <optgroup label="filter1">
              <option>option1</option>
              <option>option2</option>
              <option>option3</option>
              <option>option4</option>
            </optgroup