Au nez et à la barbe de quelqu’un is a French idiom that translates literally to “at somebody’s nose and beard of somebody” and means “right under your nose”.
Au nez et à la barbe de quelqu’un

Example sentences
This first example sentence uses s’échapper, a reflexive verb meaning “to escape”. En se déguisant, literally “while disguising”, is an example of the French gerund.
Le prisonnier s’est échappé au nez et à la barbe des gardiens en se déguisant en employé.
The prisoner escaped right under the guards’ nose by disguising himself as an employee.
Interestingly, the verb voler means both to fly and to steal.
Le voleur a volé le tableau au nez et à la barbe des gardiens.
The thief stole the painting right under the guards’ noses.


