function getDomPath(el) {
  var stack = [];
  while ( el.parentNode != null ) {
    console.log(el.nodeName);
    var sibCount = 0;
    var sibIndex = 0;
    for ( var i = 0; i < el.parentNode.childNodes.length; i++ ) {
      var sib = el.parentNode.childNodes[i];
      if ( sib.nodeName == el.nodeName ) {
        if ( sib === el ) {
          sibIndex = sibCount;
        }
        sibCount++;
      }
    }
    if ( el.hasAttribute('id') && el.id != '' ) {
      stack.unshift(el.nodeName.toLowerCase() + '#' + el.id);
    } else if ( sibCount > 1 ) {
      stack.unshift(el.nodeName.toLowerCase() + ':eq(' + sibIndex + ')');
    } else {
      stack.unshift(el.nodeName.toLowerCase());
    }
    el = el.parentNode;
  }
  return stack.slice(1); // removes the html element
}

//Usage:
var path = getDomPath(document.getElementById('button'));
console.log(path.join(' > '));