User commands in TexStudio: how to refer to the current folder?

When I go to TexStudio -> Options -> Configure TexStudio -> Build -> User Commands, I can add arbitrary shell commands. Inside the commands, I can use the character % to refer to the current file name – without extension and without folder. How can I refer to the folder of the current file?

The manual says: "If you need more options (e.g. absolute paths) use ? and look at the instruction on the bottom of the configuration dialog." But I did not find these instructions.