<nav class="navbar navbar-inverse fixed-top">
    <div class="container-fluid">
        <ul class="nav navbar-nav">
            <li>@Html.ActionLink("Menu Item 1", "Index", "Controller1")</li>
            <li>@Html.ActionLink("Menu Item 2", "Index", "Controller2")</li>
            <li>@Html.ActionLink("Menu Item 3", "Index", "Controller3")</li>
        </ul>
    </div>
</nav>

if (IsSectionDefined("SubMenu"))
{
    <nav class="navbar navbar-inverse fixed-top">
        <div class="container-fluid">
            <ul class="nav navbar-nav">
                @RenderSection("SubMenu")
            </ul>
       </div>
    </nav>
}

if (IsSectionDefined("SubSubMenu"))
{
    <nav class="navbar navbar-inverse fixed-top">
        <div class="container-fluid">
            <ul class="nav navbar-nav">
                @RenderSection("SubSubMenu")
            </ul>
        </div>
    </nav>
}

<script>
    $(document).ready(function (e) {
        $(".navbar li a").click(function () {
            $(".navbar li a").removeClass("selected");
            $(this).addClass("selected");
        });
    });
</script>

@section SubMenu {
    <li>@Html.ActionLink("SubMenu Item 1", "SubMenu1")</li>
    <li>@Html.ActionLink("SubMenu Item 2", "SubMenu2")</li>
    <li>@Html.ActionLink("SubMenu Item 3", "SubMenu3")</li>
}

@section SubSubMenu {
    <li>@Html.ActionLink("SubSubMenu Item 1", "SubSubMenu1")</li>
    <li>@Html.ActionLink("SubSubMenu Item 2", "SubSubMenu2")</li>
    <li>@Html.ActionLink("SubSubMenu Item 3", "SubSubMenu3")</li>
}