It does not help at all. After moving the files into the folder, in which they already are, the filter option is being shown. If a file is added by the extend media upload plugin, the folder will be shown in the filter menu. Nevertheless, all the other files I uploaded with the media_handle_upload function will Not shown, if I filter by this folder. I have to move these files with the moving function of the plugin into the folder, in which they already are. It does not change anything, but after that, the filter takes effect on these files.
The folder of these files is identified correctly as I can it in the last column. But this folder information is not passed to the filter list.
I did some code analysis but I did not find the right function to modify yet.
