Divi mobile menu collapsable submenus with an arrow

script.js

<script >
    jQuery(function($) {
        $(document).ready(function() {
            $("body ul.et_mobile_menu li.menu-item-has-children, body ul.et_mobile_menu  li.page_item_has_children").append('<a href="#" class="mobile-toggle"></a>');
            $('ul.et_mobile_menu li.menu-item-has-children .mobile-toggle, ul.et_mobile_menu li.page_item_has_children .mobile-toggle').click(function(event) {
                event.preventDefault();
                $(this).parent('li').toggleClass('dt-open');
                $(this).parent('li').find('ul.children').first().toggleClass('visible');
                $(this).parent('li').find('ul.sub-menu').first().toggleClass('visible');
            });
            iconFINAL = 'P';
            $('body ul.et_mobile_menu li.menu-item-has-children, body ul.et_mobile_menu li.page_item_has_children').attr('data-icon', iconFINAL);
            $('.mobile-toggle').on('mouseover', function() {
                $(this).parent().addClass('is-hover');
            }).on('mouseout', function() {
                $(this).parent().removeClass('is-hover');
            })
        });
    }); 
</script>

style.css

/*change hamburger icon to x when mobile menu is open*/

#et_mobile_nav_menu .mobile_nav.opened .mobile_menu_bar::before,
.et_pb_module.et_pb_menu .et_mobile_nav_menu .mobile_nav.opened .mobile_menu_bar::before {
	content: '\4d';
}

/*adjust the new toggle element which is added via jQuery*/

ul.et_mobile_menu li.menu-item-has-children .mobile-toggle,
ul.et_mobile_menu li.page_item_has_children .mobile-toggle,
.et-db #et-boc .et-l ul.et_mobile_menu li.menu-item-has-children .mobile-toggle,
.et-db #et-boc .et-l ul.et_mobile_menu li.page_item_has_children .mobile-toggle {
	width: 44px;
	height: 100%;
	padding: 0px !important;
	max-height: 44px;
	border: none;
	position: absolute;
	right: 0px;
	top: 0px;
	z-index: 999;
	background-color: transparent;
}


/*some code to keep everyting positioned properly*/

ul.et_mobile_menu>li.menu-item-has-children,
ul.et_mobile_menu>li.page_item_has_children,
ul.et_mobile_menu>li.menu-item-has-children .sub-menu li.menu-item-has-children,
.et-db #et-boc .et-l ul.et_mobile_menu>li.menu-item-has-children,
.et-db #et-boc .et-l ul.et_mobile_menu>li.page_item_has_children,
.et-db #et-boc .et-l ul.et_mobile_menu>li.menu-item-has-children .sub-menu li.menu-item-has-children {
	position: relative;
}


/*remove default background color from menu items that have children*/

.et_mobile_menu .menu-item-has-children>a,
.et-db #et-boc .et-l .et_mobile_menu .menu-item-has-children>a {
	background-color: transparent;
}


/*hide the submenu by default*/

ul.et_mobile_menu .menu-item-has-children .sub-menu,
#main-header ul.et_mobile_menu .menu-item-has-children .sub-menu,
.et-db #et-boc .et-l ul.et_mobile_menu .menu-item-has-children .sub-menu,
.et-db #main-header ul.et_mobile_menu .menu-item-has-children .sub-menu {
	display: none !important;
	visibility: hidden !important;
}


/*show the submenu when toggled open*/

ul.et_mobile_menu .menu-item-has-children .sub-menu.visible,
#main-header ul.et_mobile_menu .menu-item-has-children .sub-menu.visible,
.et-db #et-boc .et-l ul.et_mobile_menu .menu-item-has-children .sub-menu.visible,
.et-db #main-header ul.et_mobile_menu .menu-item-has-children .sub-menu.visible {
	display: block !important;
	visibility: visible !important;
}


/*adjust the toggle icon position and transparency*/

ul.et_mobile_menu li.menu-item-has-children .mobile-toggle,
.et-db #et-boc .et-l ul.et_mobile_menu li.menu-item-has-children .mobile-toggle {
	text-align: center;
	opacity: 1;
}


/*submenu toggle icon when closed*/

ul.et_mobile_menu li.menu-item-has-children .mobile-toggle::after,
.et-db #et-boc .et-l ul.et_mobile_menu li.menu-item-has-children .mobile-toggle::after {
	top: 10px;
	position: relative;
	font-family: "ETModules";
	content: '\33';
	color: #FF4613;
	background: #f0f3f6;
	border-radius: 50%;
	padding: 3px;
}


/*submenu toggle icon when open*/

ul.et_mobile_menu li.menu-item-has-children.dt-open>.mobile-toggle::after,
.et-db #et-boc .et-l ul.et_mobile_menu li.menu-item-has-children.dt-open>.mobile-toggle::after {
	content: '\32';
}


/*add point on top of the menu submenu dropdown*/

.et_pb_menu_0.et_pb_menu .et_mobile_menu:after {
	position: absolute;
	right: 5%;
	margin-left: -20px;
	top: -14px;
	width: 0;
	height: 0;
	content: '';
	border-left: 20px solid transparent;
	border-right: 20px solid transparent;
	border-bottom: 20px solid #ffffff;
}


/*adjust the position of the hamburger menu*/

.mobile_menu_bar {
	position: relative;
	display: block;
	bottom: 10px;
	line-height: 0;
}


/*force the background color and add a rounded border*/

.et_pb_menu_0.et_pb_menu .et_mobile_menu,
.et_pb_menu_0.et_pb_menu .et_mobile_menu ul {
	background-color: #ffffff!important;
	border-radius: 10px;
}