<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <nav class="navbar navbar-expand-lg navbar-light bg-light">
    <ul class="nav nav-tabs">
      <nav class="navbar navbar-expand-lg navbar-light bg-light">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        @charset "utf-8";
#men {
	font-size: 18px;
}
#men {
	font-family: Constantia, "Lucida Bright", "DejaVu Serif", Georgia, serif;
	font-size: 18px;
	font-style: normal;
	font-weight: bold;
	text-transform: uppercase;
	color: #96A9B7;
}
<link href="bootstrap-4.4.1.css" rel="stylesheet" type="text/css">
        <script src="../js/jquery-3.4.1.min.js" type="text/javascript"></script>
        <script src="../js/popper.min.js" type="text/javascript"></script>
        <script src="../js/bootstrap-4.4.1.js" type="text/javascript"><nav class="navbar navbar-expand-lg navbar-light bg-light">
  </nav>
</script><a class="navbar-brand" href="#">Navbar</a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent1" aria-controls="navbarSupportedContent1" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button>
        <div class="collapse navbar-collapse" id="navbarSupportedContent1">
          <ul class="navbar-nav mr-auto">
            <li class="nav-item active"> <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a> </li>
            <li class="nav-item"> <a class="nav-link" href="#">Link</a> </li>
            <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown1" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Dropdown </a>
              <div class="dropdown-menu" aria-labelledby="navbarDropdown1"> <a class="dropdown-item" href="#">Action</a> <a class="dropdown-item" href="#">Another action</a>
                <div class="dropdown-divider"></div>
                <a class="dropdown-item" href="#">Something else here</a> </div>
            </li>
            <li class="nav-item"> <a class="nav-link disabled" href="#">Disabled</a> </li>
          </ul>
          <form class="form-inline my-2 my-lg-0">
            <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
            <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
          </form>
        </div>
        
      </nav>
    </ul>
  </nav>
</nav>
