Place a .btn-group within another .btn-group
when you want dropdown menus mixed with a series of buttons.
<!DOCTYPE HTML>
<html>
<head>
<link href="http://java2s.com/style/bootstrap.min.css" rel="stylesheet">
<!-- w w w .j av a2s .co m-->
<script src="http://java2s.com/style/jquery-1.8.0.min.js"></script>
<script src="http://java2s.com/style/bootstrap.min.js"></script>
</head>
<body style='margin:20px;'>
<div class="btn-group">
<button type="button" class="btn btn-default">1</button>
<button type="button" class="btn btn-default">2</button>
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
Dropdown
<span class="caret"></span>
</button>
<ul class="dropdown-menu">
<li><a href="#">Dropdown link</a></li>
<li><a href="#">Dropdown link</a></li>
</ul>
</div>
</div>
</body>
</html>