JQuery Найти ближайший элемент внутри div на основе события mousemove

(function ($) {
    'use strict';

    $(function () {
        var
            namespace = 'mmdm',
            //-----
            mainElementID = '#__elements_container',
            highlightClass = 'founded-element__highlight',
            //-----
            mainElement = $(mainElementID),
            movableElementContainer = $('#__movable_element_container'),
            movableElement = $('#__movable_element');

        // some utility

        function getTouch(event) {
            var touch = event;
            if (('ontouchstart' in document.documentElement) || navigator.maxTouchPoints > 0) {
                touch = event.originalEvent.touches && event.originalEvent.touches.length ? event.originalEvent.touches[0] : event;
                if (event.type === 'touchstart' || event.type === 'touchmove') {
                    touch = event.targetTouches[0] || event.changedTouches[0];
                }
            }
            return touch;
        }

        // define function(s)
        function removeHighlightClass() {
            mainElement.find('*').removeClass(highlightClass);
        }

        function findElementsWithSameYNHighlightIt(e) {
            var x, y, meOffset, el;
            meOffset = mainElement.offset();
            x = (e.pageX - meOffset.left) / 2;
            y = e.pageY - $(window).scrollTop();

            el = document.elementFromPoint(x, y);
            if (!$(el).is(mainElement) && $(el).closest(mainElementID).length) {
                $(el).addClass(highlightClass);
            }
        }

        function showMovableElement() {
            movableElement.addClass('show');
        }

        function hideMovableElement() {
            movableElement.removeClass('show');
        }

        function moveMovableElement(e) {
            var y, mecTop = movableElementContainer.offset().top;
            y = e.pageY;
            // bound move to the main movable container
            if (y >= mecTop && y <= (mecTop + movableElementContainer.outerHeight())) {
                movableElement.css({
                    'top': y - mecTop - (movableElement.outerHeight() / 2)
                });
            }
            removeHighlightClass();
        }

        // attach event(s)
        movableElementContainer
            .on('mousemove.' + namespace + ' touchmove.' + namespace + ' mouseenter.' + namespace + ' touchstart.' + namespace, function (e) {
                if (!e.defaultPrevented && e.cancelable) {
                    e.preventDefault();
                }
                //-----
                var touch = getTouch(e);
                showMovableElement();
                moveMovableElement(touch);
                findElementsWithSameYNHighlightIt(touch);
            }).on('mouseleave.' + namespace + ' touchend.' + namespace, function (e) {
            if (!e.defaultPrevented && e.cancelable) {
                e.preventDefault();
            }
            //-----
            hideMovableElement();
            removeHighlightClass();
        });
    });
})(jQuery);

* {
  box-sizing: border-box;
}

#__elements_main_container {
  display: flex;
}

#__elements_container {
  width: 500px;
}

#__movable_element_container {
  position: relative;
  width: 40px;
}

#__movable_element_container::after {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: 1px;
  height: 100%;
  background-color: #ccc;
  transform: translate(-50%);
  z-index: 1;
}

#__movable_element  {
  position: absolute;
  display: none;
  align-items: center;
  justify-content: center;
  left: 50%;
  width: 40px;
  height: 40px;
  text-align: center;
  border-radius: 50rem;
  border: 1px solid #ccc;
  background-color: #fff;
  box-shadow: 0 2px 5px rgba(0, 0, 0, .26);
  transform: translate(-50%);
  z-index: 2;
}

#__movable_element.show {
  display: flex;
}

.founded-element__highlight {
    background-color: #cecdff;
    border-radius: 3px;
}

<link href = "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.css" rel = "stylesheet"/>
<script src = "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<div id = "__elements_main_container">
  <div id = "__elements_container">
    <h1>
      A heading tag!
    </h1>
    <p>
      Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
    </p>
    <ul>
      <li>First list item</li>
      <li>Second list item</li>
    </ul>
  </div>
  <div id = "__movable_element_container">
    <i id = "__movable_element" class = "fa fa-quote-right"></i>
  </div>
</div>