The youtube video below illustrates the noise as it happens i.e. when opening or closing the door.
After much research and analysis, i successfully found the solution on my own. The round metal glides should not be loose as it will not move in sync with the door; You should just pop-up the plastic cover that protects a 14mm bolt and tighten it. It’s as simple as that.
If i did not find that solution, the part would have costed at least 60US$ on ebay + labour. You will find below the hinge we are talking about in which it is actually upside down in this picture.
As the Volkswagen Group (VAG) makes other vehicle brands Audi, skoda etc.. you might also find these types of door hinge/check in those cars manufactured by the VAG.