<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>Collapsible List Group</h2>
<p>Click on the collapsible panel to open and close it.</p>
<div class="panel-group">
<div class="panel panel-default">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" href="#collapse1">Collapsible list group</a>
</h4>
</div>
<div id="collapse1" class="panel-collapse collapse">
<ul class="list-group">
<li class="list-group-item">One</li>
<li class="list-group-item">Two</li>
<li class="list-group-item">Three</li>
</ul>
<div class="panel-footer">Footer</div>
</div>