Leon to Triacastela

Hi Stelios,
Welcome to the forum!

You can look at the bus timetables at: www.alsa.es. Enter in "León" for your Origen and "Piedrafita do Cebreiro" for your Destino and it will come up (choose a random date on the calendar as well).

Looks like buses depart at 10:15am and 4:30pm most days and the trip takes either 2:25 hours or 2:55 hours. It would probably be hard to go from León to O Cebreiro to Triacastela all in one day, especially if you wanted to find an albergue in Triacastela before it filled up (depending on what time of the year you walked). But you could see!

There is this thread as well: https://www.caminodesantiago.me/community/threads/buses-from-leon-to-ocebreiro.11275/

Hope that helps. Buen Camino!
Faith