<div class="dropdown">
<button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton2" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown button
</button>
<ul class="dropdown-menu dropdown-menu-dark" aria-labelledby="dropdownMenuButton2">
<li><a class="dropdown-item active" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Separated link</a></li>
</ul>
</div>
<body>
<div class="dropdown">
<button class="btn btn-secondary dropdown-toggle" type="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown button
</button>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
</ul>
</div>
<script src="bootstrap.bootstrap.bundle.js"></script>
</body>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown
<b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#"><form role="form">
<div class="form-group">
<label for="sel1">Select list (select one):</label>
<select class="form-control" id="sel1">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
</select>
<br>
<label for="sel2">Mutiple select list (hold shift to select more than one):</label>
<select multiple class="form-control" id="sel2">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
<option>5</option>
</select>
</div>
<!-- Bootstrap 3.3 Dropdown -->
<div class="dropdown">
<button id="dLabel" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown trigger
<span class="caret"></span>
</button>
<ul class="dropdown-menu" aria-labelledby="dLabel">
...
</ul>
</div>