JSFiddle - React, Tailwind, and code Playground

HTML

<div class='d1'>
  <span>
    <a>blee
      <span> <!-- don't select this span -->
        <span>blah</span> blah
      </span>
    </a>
  </span>
</div>

<br/>

<div class='d1'>
  <span>
    <a>blee
      <span> <!-- select this span -->
        blah blah
      </span>
    </a>
  </span>
</div>

CSS

.red {
    color: red;
}

JavaScript

$('.d1 span a > span:not(:has(span))').addClass('red');