Plex currently doesn’t support different editions/cuts of the same movie. Plex will treat those as different quality-versions of the same video. Your best shot (as-of-today) is to manually split the movies … you can then assign separate posters and some suffix to the name to distinguish the versions.
https://support.plex.tv/articles/201018248-merge-or-split-items/
Alternatively you can move those alternate versions / edition in a separate library.
There’s a long-running feature suggestion to add support for different editions/cuts to the Plex library management.
