Desktop Client on Mac doesn't work as expected

What I want to have (Target)

I have a folder on my Mac and I want to sync it to the root of my Nextcloud instance. So the folder is /Users/myuser/SyncFolder. In it is a someFile.md file. I want it in my nextcloud account in /someFile.md. All other files in that SyncFolder directory should work the same. If they change locally they should be updated in nextcloud and if they change in nextcloud, they should be updated locally (when I have internet access).

What I tried and the problem

So I thought I install the Desktop app as recommended by Nextcloud. I installed it via homebrew (brew install --cask nextcloud). It installed 34.0.1. But now I don’t find the option to configure the target setup above. Under settings there is no option to select a local directory which I want to keep synced with a directory or root in nextcloud. If I click on the connected account it says “All synced”, but where? I can click on “Sync now” but it doesn’t open an dialog or something. When I open the Finder, it shows me under “Locations” a new entry “Nextcloud” which shows me the content of my Nextcloud account, but I don’t know where the folder is on my disc. How can I open it for example via the terminal? How can i use grep in that directory? Also the files seem to not be on my disc until I open them, so they are downloaded then, so it’s slow to interact with them. This would not work when being offline while traveling.

TL;DR:

How can I have a local directory, where all my files are synced to, so I have them offline available, accessible by all my software with the mac desktop client?

So I thought I install the Desktop app as recommended by Nextcloud.

Which is not via Homebrew. The Homebrew formula is unrelated to the official offerings of Nextcloud GmbH.

But now I don’t find the option to configure the target setup above.

Because the file provider synchronization mode is the default for new setups which does not allow the specification of custom folder locations but appears as a dedicated cloud storage location in Finder.

If I click on the connected account it says “All synced”, but where?

File providers fetch actual content only on demand or if you tell them to explicitly (depends on the file provider you use). By default, they synchronize the metadata only which reduces occupied disk space to what is actually needed.

How can I open it for example via the terminal?

Check ~/Library/CloudStorage in which your Nextcloud file provider container should appear.

How can i use grep in that directory?

Just as usual, macOS handles file providers and their on-demand content loading transparently.

Also the files seem to not be on my disc until I open them, so they are downloaded then, so it’s slow to interact with them. This would not work when being offline while traveling.

You can enforce a content policy which always keeps all the content available locally. Please see our user manual in regard to that:

You can switch from file provider mode to classic synchronization mode where you can set up traditional sync folders and what to sync of your online account in the general app settings, if that does not help you.

Kind regards