JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer" width="100%"><div id="inner"></div></div>

<ul id="result"></ul>

JavaScript

var first = $('#inner').closest('div[width=100%]').attr('id');
var second = $('#inner').closest('div[width="100%"]').attr('id');

$('<li></li>').text('first: ' + first).appendTo('#result');
$('<li></li>').text('second: ' + second).appendTo('#result');