Unfortunately, this is not just a software issue, this requests designed hardware/firmware to operate in concurrent mode. Meaning be able to schedule more process in the WiFi chip, sharing antenna, switching operating channel (AP/STA).... This is not common for this kind of board. A more common scenario in mobility is STA+P2P but I've never seen really good performances in this scenario.
Your best chance is to use a separate WiFi USB dongle for AP mode and be sure to configure your AP with a non-overlapping WiFI channel to avoid interference.