JSFiddle - React, Tailwind, and code Playground
HTML
<div class="topClass">
<div class="classNameone">
<p>bit of schpiel about section 1</p>
<a href="#" class="Button">click me!</a>
</div>
<div class="classNametwo">
<p>bit of schpiel about section 2</p>
<a href="#" class="Button">click me!</a>
</div>
</div>
JavaScript
$('a').click(function(){
alert( $(this).parent().parent().find('.Button').index(this) );
});