It's not a common expression. I Googled it and found nothing obvious. Perhaps certain medical specialists talk of "bone sleep" as the sleep needed for your bones to remain healthy. But it's not an expression used in everyday English and would need to be explained.

It doesn't mean anything, as far as I know. 'Bone sleep' seems to be just two random words put together, and it's not worth worrying about. What is worth thinking about, though, is a little bit of very basic grammar. Do you remember your elementary English lessons, when you learnt how to ask questions in the present simple, with the auxiliary verb 'do'? 'Where do you live?' 'What does he do?' and so on? So your question should be this: 'What does 'bone sleep' mean?

Please give the context. Where did you hear or read this?

I'm guessing this refers to the song "Bone Sleep" by Child Bite. I am also guessing the translation is not really appropriate for a forum like this, but I don't think the lyrics matter too much in such music. I can't understand any of them.