<ul class="nav nav-pills">
  <li class="dropdown" id="menu1">
  <a class="dropdown-toggle" data-toggle="dropdown" href="#menu1">Dropdown
  <strong class="caret"></strong>
  </a>
    <ul class="dropdown-menu">
      <li><a href="#">Action</a></li>
      <li><a href="#">Another action</a></li>
      <li><a href="#">Something else here</a></li>
    </ul>
  </li>
</ul>

<div class="btn-group">
  <button class="btn dropdown-toggle" data-toggle="dropdown">Action <span class="caret"></span></button>
  <ul class="dropdown-menu">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
  </ul>
</div>

<div class="btn-group">
  <button class="btn">Action</button>
  <button data-toggle="dropdown" class="btn dropdown-toggle"><span class="caret"></span></button>
  <ul class="dropdown-menu">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
  </ul>
</div>