<div class="btn-group">

  <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">

    Action <span class="caret"></span>

  </button>

  <ul class="dropdown-menu" role="menu">

    <li><a href="#">Action</a></li>

    <li><a href="#">Another action</a></li>

    <li><a href="#">Something else here</a></li>

    <li class="divider"></li>

    <li><a href="#">Separated link</a></li>

  </ul>

</div>