JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<body>
<nav>
<div><div>a</div><div>b</div><div>c</div></div>
<div><div>a</div><div>b</div><div>c</div></div>
<div><div>a</div><div>b</div><div>c</div></div>
<div><div>a</div><div>b</div><div>c</div></div>
<div><div>a</div><div>b</div><div>c</div></div>
<div><div>a</div><div>b</div><div>c</div></div>
</nav>
<article></article>
</body>
</html>

CSS

nav {display:none;}

JavaScript

var divs = document.querySelectorAll('nav>div');
var str ='';
for(var i=0;i<divs.length;++i){
    var div1 = divs.querySelector('div:nth-of-type(1)');
    var div2 = divs.querySelector('div:nth-of-type(2)');
    var div3 = divs.querySelector('div:nth-of-type(3)');
    str += div1.textContent + div2.textContent + div3.textContent;
}
document.querySelector('article').innerHTML = str;