Arduino Project

I need an Arduino based program for hidden mesh communication over wifi + Bluetooth for ESP boards where one of the boards will be acting as MQTT Server + (MQTT Client for another MQTT Server) and in case the local MQTT Server (one of the boards) is offline, then the other boards will communicate through the mesh without affecting their communication and functions.
All boards can be programmed OTA.
The boards that have Nextion screen can update and send the graphic file OTA.
Boards can communicate over Modbus (Wifi+serial) for the related points while the board with MQTT Server can report all the MQTT points over Modbus too.
Adding BACnet Protocol is +