JSFiddle - React, Tailwind, and code Playground
HTML
<div class="item-list">
<ul>
<li class="column-1">test</li>
<li class="column-1">test</li>
<li class="column-2">test</li>
<li class="column-2">test</li>
</ul>
</div>
CSS
.first {
background:green;
}
JavaScript
//$('div.item-list > ul > li.column-1:first-child,div.item-list > ul > li.column-2:first-child').addClass('first');
$('div.item-list > ul li').closest('.column-1').closest('.column-2').first().addClass('first');
//$('div.item-list > ul li').closest('.column-2').first().addClass('first');