Remove part of one field and append to another field

[ohrenkino]

@ngervae

I don't know why $regexp() doesn't work in the Replace box

$regex() is a scripting function that can only be used in Format strings. In the action of the type "Replace with regular expression" you have to enter just the patterns that in the end make up the regular expression.
And if in doubt, check the documentation:

Quick Actions and Action Groups

Mp3tag for Mac provides a variety of Actions, which can be used on filenames and tags. The actions can be applied individually via Actions → Quick Actions ⌥⌘ 6 or be grouped into named and reusable Action Groups via Actions → Actions ⌘ 6. Action Groups serve as repeatable workflows in Mp3tag for Mac. When using Quick Actions you can select one of the different available action types from the list. This action will be applied to the selected files and the changes are saved immediately. Tip 1…