Bootstrap Navbar on WordPress with merged menus

bootstrap_merged_menu_example.php

<nav id="top-navbar" class="navbar navbar-default navbar-fixed-top" role="navigation">
	<!-- Brand and toggle get grouped for better mobile display -->
	<div class="navbar-header">
		<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="navbar-collapse-1">
			<span class="sr-only">Toggle navigation</span>
			<span class="icon-bar"></span>
			<span class="icon-bar"></span>
			<span class="icon-bar"></span>
		</button>
		<a class="navbar-brand" href="/" rel="home">
			My Website
		</a>
	</div>
	<div class="collapse navbar-collapse" id="navbar-collapse-1">
		<ul class="nav navbar-nav">			  
			<?php
				/* Show the primary menu
				 */
				wp_nav_menu( array(
					'menu'                  => 'primary',
					'theme_location'        => 'primary',
					'container'             => false,
					'depth'                 => 2,
					'items_wrap'            => '%3$s',
					'fallback_cb'           => 'wp_bootstrap_navwalker::fallback',
					'walker'                => new wp_bootstrap_navwalker())
				);
				
				/* Create a social menu that displays icons for social networks
				 * it is special because it needs to integrate with the existing links
				 */
				wp_nav_menu( array(
					'menu'                  => 'social',
					'theme_location'        => 'social',
					'container'             => false,
					'depth'                 => 1,
					'items_wrap'            => '%3$s',
					'fallback_cb'           => 'wp_bootstrap_navwalker::fallback',
					'walker'                => new wp_bootstrap_navwalker())
				);
			?>
		</ul>
	</div>
</nav>

Example uses twittem/wp_bootstrap_navwalker as a custom menu walker.