JSFiddle - React, Tailwind, and code Playground
HTML
<div id="teste1">
<a id="a1">teste1</a>
<a id="a2">teste2</a>
</div>
<div id="teste2">
<a id="a1">teste1</a>
<a id="a2">teste2</a>
</div>
JavaScript
var main = document.getElementById('teste1');
console.log(main.getElementsByTagName('a')[0]);