JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test">
    <span>test</span>
</div>

JavaScript

var child = document.getElementById('test').children;
    var childrensSpan = [];
    
    for(var i = 0; i < child.length; i++){
        if(child[i].tagName === "SPAN") childrensSpan.push(child[i])
    }
    
    console.log(childrensSpan)