śubharātri
Namaste.Suprabhatam
You don't. Buddhism is a religion, not a language. You might as well ask "How do you say hello in Protestantism?".
In Telugu, to say "good night" you would say "శుభరాత్రి" (shubharatri).
good night in samoa
To say good night in Tagalog, you can say "Magandang gabi."
I would say thank you and wish my conversation partner a good night too.
You can say "good night" in Malayalam as "shubharathri."
You can (try to) say Yá'át'ééh hiiłchi'į'
To say "good night dad" in French, say Bonne nuit, papa.
"Kammagar" is how you say good night in Chuukese.
In Afghanistan, you can say "Shab bekheir" to wish someone good night.