Filters can only be saved locally?

these Filters can only be saved locally?

If this project file is opened on another computer, are these still there?

Filters are not stored as part of the font, but locally on your Mac. Opening the Glyphs file on a different Mac will show the filters that are set up on that other Mac. If you work on multiple Macs, you can copy the CustomFilters.plist file from one Mac to the other to have the same filters on both.

You can put the file into a shared folder (dropbox, iCould or GitHub) and put a symlink into the Application Support/Glyphs 3

Where is this file?

In ~/Application Support/Glyphs 3

I can’t find this on my computer.
Cannot find out anything.

In Glyphs, go to 脚本 → 打开脚本文件夹:

A Finder window will open, showing the CustomFilter.plist file: