Moving Only the Specified Track?

By default, when I use an action to move a file into a new directory, it moves everything in the file's current directory with it. In most cases, this is good. However, such as when I'm renaming and moving a single MP3 from my Downloads directory, this is kind of catastrophic moving everything else that happens to also be in the directory with it.

Is there something that I can put into an action to tell it to move only the file or files listed in the MP3TAG main pane?

Which action is that? Could you show us the parameters?
Also, see the documentation:

and in general: if you want to move folders, rename the folder (_DIRECTORY) , if you want to move single files, rename only the file (_FILENAME).

Ah, a good point. Can I put the new directory into the _FILENAME field? I wouldn't have thought that it could accept a directory path too.

The Actions that I have created do set the _DIRECTORY field, so that explains that. As with so many things, it's kind of obvious after you learn it, but not necessarily before.

You can enter a fully qualified filename which means that it may feature the full path including volume.

Thanks! I created this action, "Move Files (Single Track), for the Field _FILENAME:

/Volumes/PublicXl/data/media/music/$if2(%ALBUMARTISTSORT%,%ARTIST%)/%YEAR% %TITLE%/01 - %TITLE%

which now does it beautifully.

I subscribe to Peter Gabriel's Bandcamp, which releases a lot of single tracks, so this will be quite useful.