JSFiddle - React, Tailwind, and code Playground

HTML

<br/>
<div id="nav">
<li>
    <a id="menuDashboard">Dashboard</a>
    <ul>
        <li><strong>Sub Category</strong></li>
        <li><a href="http://jsfiddle.net/VBLS8/2/show/">Sample 1</a></li>
        <li><a href="http://jsfiddle.net/VBLS8/2/show/">Sample 2</a></li>
    </ul>
    
</li>
<li>
    <a id="menuContacts">Contacts</a>
    <ul>
        <li><strong>Companies</strong></li>
        <li><a href="http://jsfiddle.net/VBLS8/2/show/">Add Company</a></li>
        <li><a href="http://jsfiddle.net/VBLS8/2/show/">View Company</a></li>
    </ul>
</li>
</div>

CSS

#nav {
    float: left;
    margin-left:5px;
    margin-top:-20px;
    top:0;
    left:0;
    width: 100%; 
    list-style:none;
}
#nav li a {
    display: block; 
    padding: 8px 10px;
    margin-bottom:0;
    background: #666666; 
    border-top: 1px solid #EEEEEE; 
    border-bottom: 1px solid #EEEEEE; 
    text-decoration: none; 
    color: #EEEEEE;
    width:155px;
}
#nav li a:hover, #nav li a.active {
    background: #F36F25; 
    color: #FFFFFF;
    cursor:pointer;
}
#nav li ul {
    display: none;
    list-style:none;
}
#nav li ul li {
    margin-top:0;
    margin-right:0;
    margin-bottom:0;
    margin-left:-40px;
}
#nav li ul li a {
    background: #EEEEEE;
    color:#666666;
    border:1px solid #EEEEEE;
}
#nav li ul li a:hover {
    background: #EEEEEE;
    color:#f36f25;
    border:1px solid #f36f25;
}

JavaScript

$(document).ready(function(){
    //Loop through nav items, compare to expanded item ID from sessionStorage so we can expand whichever item was previously expanded
    if(sessionStorage.getItem("activeMenuItemID") != undefined){
        $("#nav > li > a").each(function(){
            if ($(this).attr("id") == sessionStorage.getItem("activeMenuItemID")){
                expandMenuItem(this);
            }
        });
    }
                  
    $('#nav > li > a').click(function(elem){
        expandMenuItem(this);
    });
    
});

function expandMenuItem(elem){
    if ($(elem).attr('class') != 'active'){
        $('#nav li ul').slideUp();
        $('#nav > li > a').removeClass("active");
        $(elem).addClass("active");
        $(elem).next().slideToggle();
        sessionStorage.setItem("activeMenuItemID", $(elem).attr("id"));
    }
}