nav bar part float right
<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css"/>
<style>
/* Stackoverflow preview fix, please ignore */
.navbar-nav {
flex-direction: row;
}
.nav-link {
padding-right: .5rem !important;
padding-left: .5rem !important;
}
</style>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-primary rounded">
<a class="navbar-brand" href="#">Navbar</a>
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link">Left Link 1</a>
</li>
<li class="nav-item">
<a class="nav-link">Left Link 2</a>
</li>
</ul>
<ul class="navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link">Right Link 1</a>
</li>
<li class="navbar-item">
<a class="nav-link">Right Link 2</a>
</li>
</ul>
</nav>
</body>