Hi, it cant quite be done with the current version , BUT it is possible with the version currently in development, this should be released by Monday so Ill tell you how you’ll be able to do it , whilst I think of it.
You can’t do it with the ‘Tag from Filename’ because this only provides an automatic mapping at the moment from Filename to tag depending upon the data it finds on a per tag basis, but you can do it with the editing functions.
Select all your artist fields , right click ‘Delete’
Drag the Artist column so that it is next to the ‘Filename’ column
Select all fields in both columns, right click ‘Prepend to Right’, this will copy the value from the filename field into the corresponding artist field, row by row.
Open Find/Replace, and limit the column to ‘Artist’, select to find .mp3 and replace with . , and select ‘Replace All’
Run ‘Correct Album’ to remove the .
Your’e done