Kind of hard linked file

Let us say I am in a npo with a choir and an orchestra. I have to manage scores and lyrics in a directory with “A” “B” “C” … subdirectories, and sub-sub-directories with the name of the song containing all its stuff (piano score, guitare tabs, choir score, lyrics, lilypond files…). Let us say they are some groups on the cloud with shared folders “orchestra”, “choir” with sub folders (by event for example).
Is it an app to make, in the event directory, a kind of hard links of the scores stored in the alpha tree ?
Thanks for your suggestions.

Shares by tag would be great:

Not sure if it works, you could create a user for each event, and then just share the files for this events with this user.

Other ideas: create an app that can do that.
On Linux, you could create this library of documents and then hard-link in the filesystem. These folders then can be used within Nextcloud. Perhaps with the workflow app, you can try to automize this (creating a tag for each event, and the workflow stuff creates the hard links).