http://jsfiddle.net/2Smgv/224/

<div class="navbar navbar-fixed-top">
<div class="navbar-inner">
<div class="container-fluid">
<a data-target=".nav-collapse" data-toggle="collapse" class="btn btn-navbar">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</a>
<a href="#" class="brand">Project name</a>
<div class="nav-collapse">
<ul class="nav">
<li class="active"><a href="#">Home</a></li>
<li><a href="#">Link</a></li>
<li><a href="#">Link</a></li>
<li><a href="#">Link</a></li>
<li class="dropdown">
<a data-toggle="dropdown" class="dropdown-toggle" href="#">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li>
<a href="#">2-level Dropdown <i class="icon-arrow-right"></i></a>
<ul class="dropdown-menu sub-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li class="nav-header">Nav header</li>
<li><a href="#">Separated link</a></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li class="nav-header">Nav header</li>
<li><a href="#">Separated link</a></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</ul>
<form action="" class="navbar-search pull-left">
<input type="text" placeholder="Search" class="search-query span2">
</form>
<ul class="nav pull-right">
<li><a href="#">Link</a></li>
<li class="divider-vertical"></li>
<li class="dropdown">
<a class="#" href="#">Menu</a>
</li>
</ul>
</div><!-- /.nav-collapse -->
</div>
</div>
</div>

<hr>

<ul class="nav nav-pills">
<li class="active"><a href="#">Regular link</a></li>
<li class="dropdown">
<a href="#" data-toggle="dropdown" class="dropdown-toggle">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu" id="menu1">
<li>
<a href="#">2-level Menu <i class="icon-arrow-right"></i></a>
<ul class="dropdown-menu sub-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li class="nav-header">Nav header</li>
<li><a href="#">Separated link</a></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li><a href="#">Separated link</a></li>
</ul>
</li>
<li class="dropdown">
<a href="#">Menu</a>
</li>
<li class="dropdown">
<a href="#">Menu</a>
</li>
</ul>

body {
padding-top: 60px;
padding-bottom: 40px;
}

.sidebar-nav {
padding: 9px 0;
}

.dropdown-menu .sub-menu {
left: 100%;
position: absolute;
top: 0;
visibility: hidden;
margin-top: -1px;
}

.dropdown-menu li:hover .sub-menu {
visibility: visible;
display: block;
}

.navbar .sub-menu:before {
border-bottom: 7px solid transparent;
border-left: none;
border-right: 7px solid rgba(0, 0, 0, 0.2);
border-top: 7px solid transparent;
left: -7px;
top: 10px;
}
.navbar .sub-menu:after {
border-top: 6px solid transparent;
border-left: none;
border-right: 6px solid #fff;
border-bottom: 6px solid transparent;
left: 10px;
top: 11px;
left: -6px;
}