In principle this should be possible. There are libraries such as RadioHead http://www.airspayce.com/mikem/arduino/ ... index.html, which can do (among other things) mesh networking. RadioHead works with the NRF24/51 family chips. However it's made for Arduino, so first it's necessary to port it to both STM32 and native NRF51822 and then integrate it into the existing code. I'd say it's possible, but definitely not trivial.
@arnaud this can be useful if you are working with quadcopter swarms and you want to quickly exchange data between the quads.