Finding Albums with multiple albumartist values

I am preparing my music collection for the use of Minimserver.
Unfortunately I have a few Albums which have more than one value for the field albumartist (i.e. different tracks within one album have different album artists), which is not accepted by Minimserver. Is there a filter expression that is able to identify those albums? All files are FLAC and every album sits in a directory of its own.
Thanks for your help.

Try filter
NOT $meta(albumartist,1) IS ""

Thanks for your kind reply. However I think your filter might not work as your suggestion will sort out album tracks that contain more than one value for albumartist within a given track (=file). Maybe my initial question has not been very clear.
My problem is, that I need to identify albums where the tracks of that specific album contain different values for albumartist from track to track (i.e. not all tracks within ONE album have the same value for albumartist).
As an example an album A with 9 tracks (files) might contain the value X for albumartist of tracks 1-4 and the value Z for tracks 5-9. I need to sort out those albums to be able to correct albumartist to the same value for all tracks of that given album because Minimserver requires all tracks within one album to have the same value for albumartist.
Thanks again.

That, indeed, I did not understand.
And now the answer is quite easy: this is not possible.
MP3tag does not compare data in different files, only data in the properties of the current file.
(There are many requests in this forum that ask for a detection of duplicats. This is also not possible.)

So you have to construct something where the current file can compare properties that are available for this file, e.g. you could rename the folder so that the artist from the first file is part of the folder name. You then compare the folder name (or parts of it) with the artist of the current file and find those where it does not match.
I do not see many more options.

In general, Mp3tag does not compare tags between files.

However, when exporting, it is possible to eliminate duplicate records.
See: https://docs.mp3tag.de/export/#export-scripting-functions
This can be used to help identify an album containing songs with different album artists.

Try this:

$filename($getEnv(USERPROFILE)\Desktop\Album List.txt,utf-16)
$loop(%album%)
$loop(%albumartist%,1)%album% - %albumartist%
$loopend()$loopend()

The result will show multiple lines for any album with multiple album artists.

QUOTE (ryerman @ May 10 2017, 16:15) <{POST_SNAPBACK}>
In general, Mp3tag does not compare tags between files.

However, when exporting, it is possible to eliminate duplicate records.
See: https://docs.mp3tag.de/export/#export-scripting-functions
This can be used to help identify an album containing songs with different album artists.

Try this:

$filename($getEnv(USERPROFILE)\Desktop\Album List.txt,utf-16)
$loop(%album%)
$loop(%albumartist%,1)%album% - %albumartist%
$loopend()$loopend()

The result will show multiple lines for any album with multiple album artists.

That did the trick for me. Thank you so much! Great forum support!