ZynSampler problem

On y Zynthian, in /zynthian/zynthian-my-data/audio there is a symlink named caption /zynthian/zynthian-my-data/caption.
ZynSampler can access mp3 files in these folder, but subfolders are not displayed. How can I access mp3 files in subfolders?
When I removed the symlink in the audio folder temporarily, Zynsampler could not find any mp3 files.