Is it safe to take advil dual action (ibuprofen & acetaminophen) before going to bed? both together is 250mg ibuprofen, 500mg acetaminophen?

It is a safe combination but you can't use it routinely, only use as needed, and do not take more than 3 days consecutively unless it is prescribed by a doctor. Furthermore, ibuprofen should not be take on an empty stomach so if you take before sleep your stomach is likely empty by then (more than 2 hours post meal) and you will have stomach issue if you take it every night.

Yes, that should cause you no harm. Good Luck