Menu multi nível

Com plugin Bootstrap-submenu http://vsn4ik.github.io/bootstrap-submenu/

by Jairo Fontes

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://vsn4ik.github.io/bootstrap-submenu/dist/css/bootstrap-submenu.min.css">
<script src="http://vsn4ik.github.io/bootstrap-submenu/dist/js/bootstrap-submenu.min.js"></script>
<nav class="navbar navbar-default">
  <div class="navbar-header">
    <button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navbar-collapse">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>

    <a class="navbar-brand">Project Name</a>
  </div>

  <div class="collapse navbar-collapse">
    <ul class="nav navbar-nav">
      <li class="dropdown">
        <a tabindex="0" data-toggle="dropdown">Dropdown<span class="caret"></span></a>

        <!-- role="menu": fix moved by arrows (Bootstrap dropdown) -->
        <ul class="dropdown-menu" role="menu">
          <li class="dropdown-submenu">
            <a tabindex="0" data-toggle="dropdown">Action</a>

            <ul class="dropdown-menu">
              <li><a tabindex="0">Sub action</a></li>
              <li class="dropdown-submenu">
                <a tabindex="0" data-toggle="dropdown">Another sub action</a>

                <ul class="dropdown-menu">
                  <li><a tabindex="0">Sub action</a></li>
                  <li><a tabindex="0">Another sub action</a></li>
                  <li><a tabindex="0">Something else here</a></li>
                </ul>
              </li>
              <li><a tabindex="0">Something else here</a></li>
              <li class="dropdown-submenu">
                <a tabindex="0" data-toggle="dropdown">Another action</a>

                <ul class="dropdown-menu">
                  <li><a tabindex="0">Sub action</a></li>
         ...

JavaScript

$('.dropdown-submenu > a').submenupicker();