Issue of Bootstrap Navbar Dropdown is opening inside Navbar - css

Question

I have made navbar using Bootstrap 4 and also using .navbar-bottom class to add scrollbar to navbar when there are more menu items than page total width.
Now, issue is that the Bootstrap 4 navbar dropdown opens inside navbar. Check this issue as shown in below Screenshot GIF.
Screenshot GIF
Check Here
.navbar-bottom class to add scrollbar to navbar
.navbar-bottom {
overflow-x: auto;
white-space: nowrap;
}
HTML
<nav class="navbar navbar-expand navbar-light navbar-bottom">
<ul class="navbar-nav mr-auto pl-2">
<li class="nav-item"><a class="nav-link px-6" href="#">Menu Item</a></li>
<li class="nav-item">
<div class="dropdown">
<a class="nav-link" href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>
<div class="dropdown-menu">
Dropdown1
Dropdown2
Dropdown3
Dropdown4
</div>
</div>
</li>
<li class="nav-item"><a class="nav-link px-6" href="#">Menu Item</a></li>
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<li class="nav-item"><a class="nav-link px-6" href="#">Menu Item</a></li>
</ul>
</nav>

Answer 1

Try this
This solve your problem
The main problem is you use dropdown class in different div instade of the li element. Hope this solve your problem.
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"></script>
<nav class="navbar navbar-expand navbar-light navbar-bottom">
<ul class="navbar-nav mr-auto pl-2">
<li class="nav-item"><a class="nav-link px-6" href="#">Menu Item</a></li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<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 px-6" href="#">Menu Item</a></li>
<li class="nav-item"><a class="nav-link px-6" href="#">Menu Item</a></li>
</ul>
</nav>