title: Web component inside another web component
body: <p>I wanted to implement a remove-button web component. It goes up the DOM, finds a certain element and removes it with itself. The problem arose when I used this component inside another component. I still could traverse the DOM outside the remove-button component, but only up to the boundaries of the parent component. Is there any way to operate the DOM outside the parent component? This is a createdCallback of my component:</p>
  
  <pre><code>proto.createdCallback = function() {
    let custom_element = this;
    let target = custom_element.getAttribute('target');
    let clone = document.importNode(template.content, true);
    clone.querySelector('input').addEventListener('click', function() {
      custom_element.closest(target).remove();
    });
    this.createShadowRoot().appendChild(clone);
  }
  </code></pre>