<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <nav class="navbar navbar-expand-md navbar-light bg-light"> <a class="navbar-brand pb-2" href="#">Navbar</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarNavDropdown"> <ul class="navbar-nav"> <li class="nav-item active"> <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="http://example.com" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Dropdown </a> <ul class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink"> <li><a class="dropdown-item" href="#">Action</a></li> <li><a class="dropdown-item" href="#">Another action</a></li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="http://google.com">Google</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Submenu</a></li> <li><a class="dropdown-item" href="#">Submenu0</a></li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Submenu 1</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Subsubmenu1</a></li> <li><a class="dropdown-item" href="#">Subsubmenu1</a></li> </ul> </li> <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Submenu 2</a> <ul class="dropdown-menu"> <li><a class="dropdown-item" href="#">Subsubmenu2</a></li> <li><a class="dropdown-item" href="#">Subsubmenu2</a></li> </ul> </li> </ul> </li> </ul> </li> </ul> </div> </nav>

.navbar-nav li:hover > ul.dropdown-menu { display: block; } .dropdown-submenu { position:relative; } .dropdown-submenu>.dropdown-menu { top:0; left:100%; margin-top:-6px; } /* rotate caret on hover */ .dropdown-menu > li > a:hover:after { text-decoration: underline; transform: rotate(-90deg); }