'keep one’s nose out of someone’s business (OR 'get one’s nose out of someone’s business') = to stop interfering in someone else’s business; to mind one’s own business. Examples: 'Keep your nose out of my business!' 'Go away! Get your nose out of my business!' 'He just can’t seem to get his nose out of other people’s business.' 'Let John have his privacy, and keep your nose out of my business, too!'

means "not to interfere in someone affairs."

Keep your nose out of our business Meaning: nothing is related to you, "Get out, it is our business, not yours"

It also is an expression used to make someone stop doing something unacceptable. Example: Keep your nose out of this icecream! Get back to your homework.