Small xmas present.
No modding needed.

AFAIK this key combination never leaked (if it already did, just delete this thread/post).

To unlock Debug, Advanced and all other hidden tabs for the next boot press:
R+N (while powered off (S5) <- yes, I am for real)
Power on the machine and enter Bios. You should see all tabs than.

Tested with some Ideapads like U330P (or similar) and 720-S ##IKB


Edit by Fernando: Thread title shortened and customized

thanks fren gonna try this on my legion after re-locking the bios happy new year btw