[Finchy]

Ok, I understand what you are trying to do.

I have not used Nodes (strange as that sounds) so I am not the best person to help and promote them. Personally I would go with Smart Playlists and add them as menu items. Have a read of this... Custom home items (wiki)

The whole moving items when you have watched them is a strange setup and adds more work and complexity than needed. If your only concern is losing watched status, then two ways to avoid this...
1. Export your library to Separate Files on a regular basis... Import-export library (wiki)
2. Used WatchedList add-on and set it for regular automatic saves... https://kodi.wiki/view/Add-on:WatchedList

Of course I am assuming you have built a library, and not simply using Kodi as a dumb file browser.

Thanks for the reply, apologies for the late response (first chance I've had!) 

I keep watched movies seperate from unwatched movies for a few reasons. Space on my main NAS is one, and also because I use Kodi, Emby and Plex on different devices (I'd love to have just Kodi on all but because it's client only and I haven't had the time to play with setting up an SQL sync it's not been an option) so if any of those has problems I don't have to fanny around trying to set them all up with watched and unwatched status. It works for me. We rarely geek/obsessive/collector in me wants to keep them all for that odd occasion I can persuase my wife to watch one again! 

I have been using smart playlists for nodes, along with widgets (I prefer Titan skin in vertical layout) but if I make changed to any playlist they often lose the shortcut links, plus all the default search categories display items from all across the movie collection, which is why I was trying to work out if nodes might help me build four or five more limited movies collections, such as the archive, pre-00s, maybe foreign language.