I've defined a custom view on a given artifact in order to show less attributes to a given "position".
I then linked the new view to the position using the "Admin / Positions ..." menu.
Actually, the view seems to be added (as the display of the artifact changed. However, the new view is not listed among the position views (Admin / Positions ...).
As such, I could add several time the relation ... and the artifact view now appears several time in the browsing view (see attachments).