Документ: метод elementsFromPoint()

elementsFromPoint(x, y)

<div>
  <p>Some text</p>
</div>
<p>Elements at point 30, 20:</p>
<div id="output"></div>

let output = document.getElementById("output");
if (document.elementsFromPoint) {
  let elements = document.elementsFromPoint(30, 20);
  elements.forEach((elt, i) => {
    output.textContent += elt.localName;
    if (i < elements.length - 1) {
      output.textContent += " < ";
    }
  });
} else {
  output.innerHTML = `<span style="color: red">
  Browser does not support
  <code>document.elementsFromPoint()</code>
</span>
`;
}