Open Genesis Primary and Secondary Navigation with a Single Responsive Menu Icon - https://amethystwebsitedesign.com/open-genesis-primary-and-secondary-navigation-with-a-single-responsive-menu-icon/

functions.php

<?php
//* Do NOT include the opening php tag

/* Edit (or add) the enqueue line for the responsive menu */
//* Enqueue Scripts
add_action( 'wp_enqueue_scripts', 'executive_load_scripts' );
function executive_load_scripts() {

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

}

/* 
//*Comment out the following in functions.php
//* Remove the site description
remove_action( 'genesis_site_description', 'genesis_seo_site_description' );

//* Reposition the secondary navigation menu
remove_action( 'genesis_after_header', 'genesis_do_subnav' );
add_action( 'genesis_footer', 'genesis_do_subnav', 7 );

//* Reduce the secondary navigation menu to one level depth
add_filter( 'wp_nav_menu_args', 'executive_secondary_menu_args' );
function executive_secondary_menu_args( $args ){

	if( 'secondary' != $args['theme_location'] )
	return $args;

	$args['depth'] = 1;
	return $args;

}*/

responsive-menu.js

/* Responsive menu code - add to child theme folder /js/  */

jQuery(function( $ ){

	$(".genesis-nav-menu").addClass("responsive-menu");
	$('<div class="responsive-menu-icon"></div>').insertBefore( '.nav-primary .genesis-nav-menu' );

	$(".responsive-menu-icon").click(function(){
		$(".genesis-nav-menu").slideToggle();
		$(this).toggleClass("menu-open");
	});

	$(window).resize(function(){
		if(window.innerWidth > 800) {
			$(".genesis-nav-menu, nav .sub-menu").removeAttr("style");
			$(".responsive-menu > .menu-item").removeClass("menu-open");
		}
	});

	$(".responsive-menu > .menu-item").click(function(event){
		if (event.target !== this)
		return;
			$(this).find(".sub-menu:first").slideToggle(function() {
			$(this).parent().toggleClass("menu-open");
		});
	});

});