Default directory for macro output doesn't work

[jademan]

If I define a specific folder for the macro output, let’s say “test”, the mp3 file will created into "test\macro-output" folder.

Yes. According to Audacity Manual - Apply Macro:

• If the project has been Saved, then the exported files will be saved in a folder named “macro-output”. The “macro-output” folder will be in the location specified in Directories Preferences.
• If the audio in the project came from an imported file as its initial step (that is, it is a named project), the “macro-output” folder will also be in the location specified in Directories Preferences.

Also in Directories Preferences, we see:

• If you set a default folder for Macro output Audacity will create a folder called “macro-output” in that folder and that will be used for exports from Macros.

If you want to see pre-3.0.2 macro behavior, please see this thread: Legacy macro-output folder