<div class="u_debug__sibling">
  Sibling container div
</div>

    <ul class="txp-dropdown ui-menu ui-widget ui-widget-content" id="ui-id-13" role="menu" tabindex="0">
      <li class="txp-dropdown-toggle-all ui-menu-item">
        <div id="ui-id-14" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="select_all" type="checkbox" tabindex="-1" value="all"> Toggle all/none selected</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-15" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="id"> ID#</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-16" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="title_body_excerpt"> Title, body and excerpt</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-17" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="section"> Section</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-18" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="keywords"> Keywords</label>
        </div>
      </li>
      <li class="ui-menu-item selected">
        <div id="ui-id-19" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox active" name="search_method[]" type="checkbox" checked="checked" tabindex="-1" value="categories"> Categories</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-20" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="status"> Status</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-21" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="author"> Author</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-22" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="article_image"> Article image</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-23" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="posted"> Posted</label>
        </div>
      </li>
      <li class="ui-menu-item">
        <div id="ui-id-24" tabindex="-1" role="menuitem" class="ui-menu-item-wrapper">
          <label>
            <input class="checkbox" name="search_method[]" type="checkbox" tabindex="-1" value="lastmod"> Modified</label>
        </div>
      </li>
    </ul>

<div class="u_debug__sibling">
  Sibling container div
</div>