In case you didn't know, the save files of The Witcher (extension .TheWitcherSave) are interchangeable between WINDOWS and APPLE.
That means you can use your Witcher save files from Windows on your Mac and viceversa, if you copy them to the correct folder.

The reason being that the Mac version is basically the Windows version that is able to run on a Macintosh thanks to WineSkin, a wonderful tool that helps making ports of these games possible.

It is not the scope of this brief note to go into details about WineSkin, but Google can help you find out more.
:)

Thanks for the info!

I know it's very old post, but I have problem, that I can't find correct folder on my Mac with saves :( I have saves from my windows computer but I don't know where I need to put them :(

Thanks for every help!

https://pcgamingwiki.com/wiki/The_Witcher#Save_game_data_location