btn grup dropdown
<div class="btn-group">
<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-toggle="dropdown">
Sony <span class="caret"></span></button>
<ul class="dropdown-menu" role="menu">
<li><a href="#">Tablet</a></li>
<li><a href="#">Smartphone</a></li>
</ul>
</div>
</div>