The Organelle hides items that begin with “.” and unfortunately there isn’t a setting to make it show them, so I think you’ll have to ssh into the Organelle to fix it.
With the Organelle connected, open a terminal ssh
ssh music@organellem.local
(you can replace organellem.local with the IP found in Settings->Info if it is not working) Password is ‘coolmusic’.
Then to rename it:
cd /sdcard/Patches
mv .Synthesizers Synthesizers