JSFiddle - React, Tailwind, and code Playground

HTML

<div>       
        <br />
     <a name="IDATLQHE"></a>
    <h2 class="subhead" xmlns="">
    <dev>
        <dd>
            <span>abcd</span>
        </dd>

        <rr>
            <span>
                    <a title="google" href="http://google.com">google.com</a>
            </span>
       </rr>                    
    </dev>
    </h2>       
</div>

JavaScript

var devs = document.getElementsByTagName('dev');
for(var i = 0, len = devs.length; i < len; i++)
{
    var dev = devs[i],
        h2 = dev.getElementsByTagName('rr'),
        h3 = dev.getElementsByTagName('dd');
    if(h2.length === 1)
    {
        var aa= h2[0],
        aaa=aa.getElementsByTagName('a');
        if(h2.length === 1 && h3.length === 1)
        {
            aaa[0].innerHTML = h3[0].innerHTML;
            h3[0].innerHTML="";
        }
    }
}