How can I exclude a local subfolder from syncing?

Let’s say I work in LocalFolder and I have a folder sync connection in my Nextcloud desktop client that I use for mirroring stuff from LocalFolder to ServerFolder.

However, there are some subfolders in LocalFolder that I don’t want to be synced to ServerFolder (for whatever reason).

How can I achieve this?

My intuition was to remove the tick from the checkbox in the folder sync connection’s folder list, but that does the opposite (it removes the subfolder from LocalFolder and leaves it in ServerFolder).