JSFiddle - React, Tailwind, and code Playground

HTML

<ul>    
    <li id="first">First</li>
    <li id="second">Second</li>
    <li id="third">Third
    <ul>    
    <li id="first1">1</li>
    <li id="second2">2</li>
    <li id="third3">3</li>
</ul>
    </li>
</ul>

CSS

#second, #third { display: none; }

JavaScript

$(document).ready(function(){
    
   $('#third').nextAll('li').show(); 
});