JSFiddle - React, Tailwind, and code Playground

HTML

<div class="mainmenu clearfix">
  <ul class="submenu-class">
    <li><a href="#">Open Menu 01</a></li>
    <li><a href="#">Dropdowns  </a>
      <ul class="mainmenu-submenu">
        <li><a href="#">Dummy Sub menu style 01</a></li>
        <li><a href="#">Dummy Sub menu style 01</a></li>
        <li><a href="#">Dummy Sub menu style 01</a></li>
        <li><a href="#">Dummy Sub menu style 01</a></li>
        <li><a href="#">Dummy Sub menu style 01</a>
          <ul class="mainmenu-submenu-sub">
            <li><a href="#">Dummy Sub menu style 02</a></li>
            <li><a href="#">Dummy Sub menu style 02</a></li>
            <li><a href="#">Dummy Sub menu style 02</a></li>
            <li><a href="#">Dummy Sub menu style 02</a>
              <ul class="mainmenu-submenu-sub-sub">
                <li class=""><a href="#">Dummy Sub menu style 03</a></li>
                <li class=""><a href="#">Dummy Sub menu style 03</a></li>
                <li class=""><a href="#">Dummy Sub menu style 03</a></li>
                <li class=""><a href="#">Dummy Sub menu style 03</a></li>
              </ul>
            </li>
          </ul>
        </li>
      </ul>
    </li>
    <li><a href="#">Open Page text Menu 01  </a>
      <div class="megamenu clearfix">
        <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
      </div>
    </li>
    <li><a href="#">Open Page text Menu 01  </a>
      <div class="megamenu clearfix" > Lorem Ipsum is simply dummy text...

CSS

.clearfix:before, .clearfix:after{content: ""; display: table;}.clearfix:after{clear: both;}.clearfix{zoom: 1;}.cl{clear: both;}
ul, ol{margin-top:0px; margin-right:0px; margin-left:0px;  margin-bottom:0px; -webkit-box-sizing: border-box; -moz-box-sizing: border-box;    box-sizing: border-box; padding:0px ; list-style:none;}
 
.submenu-class li a{
	display:block;
	background-color:#fff;
	color:#424242;
	padding:0px 14px; line-height:48px;
	border-right:1px solid rgba(0,0,0,0.10);
	text-decoration:none;}
  
 
.mainmenu-click {
	position:absolute;
	top:0;
	right:0;
	display:block;
	cursor:pointer;
	width:100%;
	}

.mainmenu-click i{
	float:right;
	display:block;
	height:23px;
	width:25px;
	margin-top:11px;
	margin-right:8px;
	background-size:25px;
	font-size:21px;
	color:rgba(0,0,0,0.25);
	
	}

 
.mainmenu-submenu-sub{
	width:100% ;
	position:static ;
	left:100% ;
	top:0 ;
	display:none;
	margin:0px ;
	padding:0px ;
	border:solid 0px ;
	transform:none ;
	opacity:1 ;
	visibility:visible ;
	}
	
.mainmenu-submenu-sub li{
	margin:0px 0px 0px 0px ;
	padding:0px;
	position:relative;}
	
.mainmenu-submenu-sub a{
	display:block;
	padding:10px 25px 10px 25px;
	border-bottom:solid 1px #ccc;
	font-weight:normal;}
	
 

.mainmenu-submenu-sub-sub{
	width:100% ;
	position:static ;
	left:100% ;
	top:0 ;
	display:none;
	margin:0px ;
	padding:0px ;
	border:solid 0px ;
	transform:none ;
	opacity:1 ;
	visibility:visible ;
	}
	
.mainmenu-submenu-sub-sub li{
	margin:0px 0px 0px 0px ;}
	
.mainmenu-submenu-sub-sub a{
	display:block;
	color:#000;
	padding:10px 25px;
	background:#000 ;
	border-bottom:solid 1px #ccc;
	font-weight:normal;}
	
 
.mainmenu{position: relative;}

.arrowupdown{ width:9px; height:9px; background-color:#ccc; }
	
.mainmenu .submenu-class li{
	width:240px;
	display:block;
	float:none;
	border-right:none;
	background-color:transparent;
	position:relative;
	white-space:inherit;}
	
.mainmenu .submenu-class  li  a{
	padding:9px 32px 9px...

JavaScript

$(function() {
	 
	$('.submenu-class li').has('.mainmenu-submenu, .mainmenu-submenu-sub, .mainmenu-submenu-sub-sub').prepend('<em class="mainmenu-click"><i class="arrowupdown"></i></em>');
	
	$('.submenu-class li').has('.megamenu').prepend('<em class="mainmenu-click"><i class="arrowupdown"></i></em>');
		
	$('.mainmenu-mobile').click(function(){
		$('.submenu-class').slideToggle('slow');
	});
	$('.mainmenu-click').click(function(){
	$(this).siblings('.mainmenu-submenu').slideToggle('slow');
	$(this).children('.mainmenu-arrow').toggleClass('mainmenu-rotate');
	$(this).siblings('.mainmenu-submenu-sub').slideToggle('slow');
	$(this).siblings('.mainmenu-submenu-sub-sub').slideToggle('slow');
	$(this).siblings('.megamenu').slideToggle('slow');
		
	});

});