I want to batch change a tag (like genre) with specified content like "Theoldone" to "Thenewone". All (genre) tags which do not have the content "Theoldone" should remain untouched during the batch process.
Start by using a filter as %genre% IS Theoldone to get all tracks that should be edited. Then you can select all, and use an Action(Quick) to format the new data.