JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>A</li>
    <li>B</li>
</ul>
<ul>
    <li>C</li>
    <li>D</li>
</ul>
<a href="#" class="switch_order">Switch</a>

JavaScript

$('body').on('click', '.switch_order', function(e){
    $('ul li').each(function(i,li){
        $(this).parent().prepend(li)
    })
});