Filename remove double string

Press Alt-T to open the extended tags dialogue.
That shows you all editable tag fields in a file.

perfect, i found it
i dont know if this could be extractet to a new fileneme written from tags as you described
grafik

unknown| track-17852631

I am a little puzzled about the square in front of the word "track" - this looks like a character that cannot be displayed. Which one is it?
@LyricsLover linked a page for you so that you can investigate which character that is.
To get only the number in the Converter>Tag-Filename try
Format string: %artist%_$regexp(%uniquefileid%,.*?-(\d+),$1)

Edit: found it: it is Character 3, end_of_text ... something that should not appear in such a field.

1.how can i add this correcct field to the tags field ?

the convert from tag to filename works
with this:
%title%_$regexp(%uniquefileid%,.*?-(\d+),$1)
2.which command is that to use tag to filname in actions ?

Convert Tag -> Tag

The same command as you used it here.