<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h2>Vertical Button Group with Dropdown</h2>
<div class="btn-group-vertical">
<button type="button" class="btn btn-primary">Apple</button>
<button type="button" class="btn btn-primary">Samsung</button>
<div class="btn-group">
<button type="button" class="btn btn-primary dropdown-toggle" data-bs-toggle="dropdown">Sony</button>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Tablet</a></li>
<li><a class="dropdown-item" href="#">Smartphone</a></li>
</ul>
</div>
</div>
</div>
</body>