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-
<!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>