<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<h2>Create your snippet's HTML, CSS and Javascript in the editor tabs</h2>
</div>
</div>
<div class="btn-group">
<a href="http://google.com" class="btn btn-default dropdown-toggle" data-hover="dropdown">Lists</a>
<ul class="dropdown-menu" role="menu">
<li>
<a href="#">Sub List 1</a>
</li>
<li>
<a href="#">Sub List 2</a>
</li>
</ul>
</div>
