import { animate, utils, stagger } from 'animejs';

const [ $reverseButton ] = utils.$('.reverse');

const animation = animate('.square', {
  x: '17rem',
  ease: 'inOutSine',
  delay: stagger(100),
});

const reverseAnimation = () => animation.reverse();

$reverseButton.addEventListener('click', reverseAnimation);

<div class="medium row">
  <div class="square"></div>
</div>
<div class="medium row">
  <div class="square"></div>
</div>
<div class="medium row">
  <fieldset class="controls">
    <button class="button reverse">Reverse</button>
  </fieldset>
</div>