Need to modify export script to create single M3U file for whole Album that will point to mp3 files inside sub folders (CD1, CD2, CD3) and NOT 3 separate M3U files for each folder.
The easiest way would be to use the function File>Create Playlist (for selected files).
This will save the playlist in the current working directory.
Or see e.g. here:
I just loaded the folder "Music" with several subfolders "Album1", "Album2" etc.
Now "Music" is the working folder.
I selected files from 2 subfolders and called the function File>Playlist (for selected files).
The resulting, single playlist looks like this: #EXTM3U #EXTINF:552,Babel - Jerry Sprunger - Lemi Vice & Action Jackson Remix (Dirty) Ambient Diary.One - 1997\ambient Diary.One _ 001 _ Babel _ The Return - of Babel''.mp3
... #EXTINF:309,Index ID - Federflug Ambient Diary.Three - 2000\Ambient Diary.Three _ 105 _ Index ID _ Federflug.mp3
...
Don't have this option, unless you mean Entries relative from work directory - Enable this option, if you don't want full file paths in your playlist, it made no difference checked or unchecked.
There is no way to handle how Mp3Tag creating M3U files within export script other than specify file name and encoding.
Still weather to create one file or file for each sub folder is determined by Mp3Tag option "One file per directory" if checked it creates M3U file for each sub folder, if unchecked creates one M3U file with MP3 files from all directories, no other option.
This is limiting factor to doing what i intended.
I think only solution to my original question is workaround - create single M3U file trough export script then break it up using 3rd party program, any idea how to do it?
Also, you can define a playlist name with string constants and viariable parts where the variable part could be %album% so that you get all the files from one album into one file.
That worked, with one minor bug, sometimes sub folders within album folder have different name from CD and Disk (or have greater depth than one sub folder) in this case your script still creates M3U within albums sub-folder.
Edit: Here is my regex-less tweak to fix folder issues.