Bootstrap 4

HTML

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.2/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<body>
    <header>
        <div class="container">
            <nav class="navbar navbar-expand-lg navbar-light top">
            <div class="row">
              <div><img src="https://via.placeholder.com/45" height="45" alt=""></div>
              <div class="col">
                <div class="div1 ">
                    <a href="#" id="id1">somthinghere</a>
                    <a href="#" class="active">link</a>
                    <a href="#" class="">link2</a>
                </div>
                <div class="div2" id="navbarsExampleDefault">
                    <ul class="navbar-nav ml-lg">
                        <li class="nav-item">
                            <a class="nav-link" href="#">link1</a>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link" href="#">link11</a>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link" href="#">link111</a>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link" href="#">link1111</a>
                        </li>
                    </ul>                       
                </div>                
              </div>
            </div>
            

            </nav>
        </div>
    </header>
</body>

CSS

header{
    position:absolute;
    z-index: 10;
    width: 100%;
}