How To Create Sub Dropdown menu in MVC 5 ?

Problem:

I needed a way to put a submenu into a menu in bootstrap in MVC 5 project.  The folks at bootstrap don't support this anymore.

Solution:

CSS:

#nav ul{
    display : none;
}
#nav li:hover > ul{
    display : block;
}

    <ul id="nav">
      <li><a href="#">Menu1</a></li>
      <li><a href="#">Menu2</a></li>
      <li><a href="#">Menu3</a></li>
      <li>
        <a href="#">Menu4</a>
        <ul>
            <li><a href="#">SubMenu1</a></li>
            <li><a href="#">SubMenu2</a></li>
            <li><a href="#">SubMenu3</a>
                <ul>
                    <li><a href="#">SubMenu11</a></li>
                    <li><a href="#">SubMenu22</a></li>
                </ul>
            </li>
        </ul>
      </li>
    </ul>

Source:

https://forums.asp.net/t/1987573.aspx?How+To+Create+Sub+Dropdown+menu+in+MVC+5+