Real madrid schools celtic 3 0 in the champions league

I think there may be some confusion here!

Real Madrid did not play Celtic in the Champions League and win 3-0. In fact, Celtic has never beaten Real Madrid in a competitive match.

However, I can suggest some possible matches that might have led to this confusion:

• Real Madrid did play Celtic in the Champions League group stage in 2013-14, and won 1-0 at the Santiago Bernabéu Stadium.
• Real Madrid also played Celtic in the Champions League group stage in 2015-16, and won 2-1 at Celtic Park.

If you're thinking of a specific match, please let me know and I can try to help you with the details!