How to split Navigation Menu in Genesis using WP Nav Plus. http://sridharkatakam.com/split-navigation-menu-genesis-using-wp-nav-plus/

functions.php

//* Remove the Header Right widget area
unregister_sidebar( 'header-right' );

// Register Header Navigation Menu
register_nav_menu( 'header', 'Header Navigation Menu' );

// Add Theme Support for Genesis Menus
add_theme_support( 'genesis-menus', array(
	'primary'   => __( 'Primary Navigation Menu', 'genesis' ),
	'secondary' => __( 'Secondary Navigation Menu', 'genesis' ),
	'header'    => __( 'Header Navigation Menu', 'genesis' ),
) );

// Add Attributes for Navigation Elements
add_filter( 'genesis_attr_nav-header', 'genesis_attributes_nav' );

// Remove the standard Header content
remove_action( 'genesis_header', 'genesis_do_header' );

// Add custom Header content
add_action( 'genesis_header', 'custom_do_header' );
function custom_do_header() {

	if ( wp_is_mobile() ) {

		echo '<a href="' . get_bloginfo( 'url' ) . '"><img class="aligncenter" src="http://cl.ly/image/3v3Q2b330y2z/logo.gif" /></a>';

		// wp_nav_menu(
		// 	array(
		// 		'menu' => 'Contributors',
		// 		'container' => 'nav',
		// 		'menu_class' => 'genesis-nav-menu'
		// 	)
		// );

		genesis_nav_menu( array(
			'theme_location' => 'header',
			'menu_class'     => 'menu genesis-nav-menu',
		) );
	}

	else {

		$divider_html = '<a href="' . get_bloginfo( 'url' ) . '"><img src="http://cl.ly/image/3v3Q2b330y2z/logo.gif" /></a>';

		wp_nav_menu(
			array(
				// 'menu' => 'Contributors',
				'theme_location' => 'header',
				'divider_html' => $divider_html,
				'container' => 'nav',
				'menu_class' => 'genesis-nav-menu'
			)
		);

	}

}

//* Enqueue Mobile Responsive Menu
add_action( 'wp_enqueue_scripts', 'mobile_responsive_menu' );
function mobile_responsive_menu() {

	wp_enqueue_script( 'mobile-first-responsive-menu', get_bloginfo( 'stylesheet_directory' ) . '/js/responsive-menu.js', array( 'jquery' ), '1.0.0' );

	wp_enqueue_style( 'dashicons' );

}

gistfile1.php

wp_nav_menu(
	array(
		// 'menu' => 'Contributors',
		'theme_location' => 'header',
		'divider_html' => $divider_html,
		'divider_offset' => 1,
		'container' => 'nav',
		'menu_class' => 'genesis-nav-menu'
	)
);

style.css

.site-header {
	min-height: 0;
}

.menu-divider-item {
	display: inline-block;
	text-align: left;
}

.menu-divider-item img {
	vertical-align: middle;
}

.menu-divider-item a {
	padding-top: 0;
	padding-bottom: 0;
}

/* Responsive Menu
--------------------------------------------- */

.responsive-menu-icon {
	cursor: pointer;
	display: none;
	margin-bottom: -1px;
	text-align: center;
}

.responsive-menu-icon::before {
	content: "\f333";
	display: inline-block;
	font: normal 20px/1 'dashicons';
	margin: 0 auto;
	padding: 10px;
}
.nav-primary .responsive-menu-icon::before {
	color: #fff;
}

/* Sub menu indicators
--------------------------------------------- */

@media only screen and (min-width: 768px) {

	.genesis-nav-menu > .menu-item.menu-item-has-children > a:after {
		content: "\f347";
		-webkit-font-smoothing: antialiased;
		font: normal 11px/1 'dashicons';
		vertical-align: bottom;
		padding-left: 8px;
	}

	ul.sub-menu li.menu-item-has-children > a:after {
		content: "\f345";
		-webkit-font-smoothing: antialiased;
		font: normal 11px/1 'dashicons';
		vertical-align: bottom;
		padding-left: 16px;
	}

}

@media only screen and (max-width: 768px) {

	.genesis-nav-menu.responsive-menu > .menu-item > .sub-menu,
	.genesis-nav-menu.responsive-menu {
		display: none;
	}

	.genesis-nav-menu.responsive-menu .menu-item,
	.responsive-menu-icon {
		display: block;
	}

	.genesis-nav-menu.responsive-menu .menu-item {
		margin: 0;
	}

	.genesis-nav-menu.responsive-menu .menu-item:hover {
		position: static;
	}

	.genesis-nav-menu.responsive-menu .current-menu-item > a,
	.genesis-nav-menu.responsive-menu .sub-menu .current-menu-item > a:hover,
	.genesis-nav-menu.responsive-menu a,
	.genesis-nav-menu.responsive-menu a:hover {
		background: none;
		line-height: 1;
		padding: 16px 20px;
	}
	.nav-primary .genesis-nav-menu.responsive-menu .current-menu-item > a,
	.nav-primary .genesis-nav-menu.responsive-menu .sub-menu .current-menu-item > a:hover,
	.nav-primary .genesis-nav-menu.responsive-menu a,
	.nav-primary .genesis-nav-menu.responsive-menu a:hover {
		color: #fff;
	}

	.genesis-nav-menu.responsive-menu .menu-item-has-children {
		cursor: pointer;
	}

	.genesis-nav-menu.responsive-menu .menu-item-has-children > a {
		margin-right: 60px;
	}

	.genesis-nav-menu.responsive-menu > .menu-item-has-children:before {
		content: "\f347";
		float: right;
		font: normal 16px/1 'dashicons';
		height: 16px;
		padding: 16px 20px;
		right: 0;
		text-align: right;
		z-index: 9999;
	}
	.nav-primary .genesis-nav-menu.responsive-menu > .menu-item-has-children:before {
		color: #fff;
	}

	.genesis-nav-menu.responsive-menu .menu-open.menu-item-has-children:before {
		content: "\f343";
	}

	.genesis-nav-menu.responsive-menu .sub-menu {
		border: none;
		left: auto;
		opacity: 1;
		padding-left: 25px;
		position: relative;
		-moz-transition:    opacity .4s ease-in-out;
		-ms-transition:     opacity .4s ease-in-out;
		-o-transition:      opacity .4s ease-in-out;
		-webkit-transition: opacity .4s ease-in-out;
		transition:         opacity .4s ease-in-out;
		width: 100%;
		z-index: 99;
	}

	.genesis-nav-menu.responsive-menu .sub-menu .sub-menu {
		margin: 0;
	}

	.genesis-nav-menu.responsive-menu .sub-menu .current-menu-item > a:hover,
	.genesis-nav-menu.responsive-menu .sub-menu li a,
	.genesis-nav-menu.responsive-menu .sub-menu li a:hover {
		background: none;
		border: none;
		padding: 12px 20px;
		position: relative;
		width: 100%;
	}

}