I too am having this same problem and it is very disappointing. Hopefully this gets changed. One hack I came up with is by setting the “dont sync folders larger than” to 0. This stops new folders from autosyncing however the downside is when someone adds a subfolder to a folder you syncing it won’t auto add either 
somebody needs to figure this out.
THANK YOU -
While it is ideal to have just the one Parent folder with a subfolder selection your workaround is Perfect.
@bness, completely understanding your situation from a project manager’s point-of-view. This solution would work for you as long as you don’t ever need to collaborate with C2 or C3. Using @najtram workaround, each person would set up a project using their Project name.
This workaround works for me. Thanks Again!!!
I think this is a strongly needed feature.
In an environment were multiple person share files and folders (the application field of NextCloud), the ability to choose to not automatically sync the subfolders of a shared folder, is really important.
Create a folder’s connection per project is not a good solution for us.
Are there any innovations here? for us, this is also super bad to use.
Yes, since version 3.2 there is the virtual files where all files are visible in the structure but without downloading everything:
The virtual files are nice to have but we have tons of folders of which I only need like 15 out of 500.
It would be really nice to have the possibility to only see the files I want without adding automatically new folders. Its also possible to set up to ask every time someone adds a new folder but thats also quite annoying if you think about everyone in the company has to do that every single time someone in the company adds a folder.
Is there any solution yet?