I try to find out how to get from Malaga to Trevelez or Lanjaron via Motril, not via Granada. I know there is a bus, since I have toke it 4 years ago but I cannot find any in the internet. I checked the Alsa.es side but I guess it was not an Alsa bus it took but some sort of school bus. Anyone who can help me finding a pdf with the schedules?
Rome2Rio is really good for this sort of thing.
Take a look here: https://www.rome2rio.com/s/M%C3%A1laga/Motril
You can then get a separate bus from Motril to either Trevelez or Lanjaron, whichever you actually prefer