<link href="//netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="container">
<div class="panel panel-default">
<div class="panel-heading librePanelHeading">
<div class="panel-title">
<b class="pull-right glyphicon glyphicon-folder-close libreMenuIcon"></b>
<a data-toggle="collapse" href="#menuPanelListGroup">
<span>Menu 1</span>
</a>
</div>
</div>
<ul class="list-group collapse in" id="menuPanelListGroup">
<li class="list-group-item librePanelListGroupItem">
<a data-toggle="collapse" href="#menuPanelSubListGroup">
<span>Item 1</span>
<b class="pull-right glyphicon glyphicon-chevron-right"></b>
</a>
<ul id="menuPanelSubListGroup" class="collapse librePanelSubListGroupItem">
<li class="list-group-item librePanelListGroupItem">
<span><a href="#">SubItem 1</a></span>
</li>
<li class="list-group-item librePanelListGroupItem">
<span>SubItem 2</span>
</li>
<li class="list-group-item librePanelListGroupItem">
<span>SubItem 3</span>
</li>
</ul>
</li>
<li class="list-group-item librePanelListGroupItem">