使用Bootstrap嵌套按钮组
将按钮组嵌套在另一个按钮组内，即，将.btn组放置在另一个.btn组内。当您希望下拉菜单与一系列按钮混合在一起时，可以完成此操作。
要嵌套按钮组，您可以尝试运行以下代码-
示例
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet">
<script src = "/scripts/jquery.min.js"></script>
<script src = "/bootstrap/js/bootstrap.min.js"></script>
</head>
<body style = "background: orange;">
<div class = "btn-group">
<button type = "button" class = "btn btn-default">Rank</button>
<button type = "button" class = "btn btn-default">Marks</button>
<div class = "btn-group">
<button type = "button" class = "btn btn-default dropdown-toggle" data-toggle = "dropdown">
Subjects
<span class = "caret"></span>
</button>
<ul class = "dropdown-menu">
<li><a href = "#">Maths</a></li>
<li><a href = "#">Science</a></li>
<li><a href = "#">English</a></li>
</ul>
</div>
</div>
</body>
</html>