I would like to connect my Raspberry Pi 3B+ to a WiFi network and use it as an access point for its own network. I need it to act as a proxy so that I can connect multiple devices and they appear as a single device on my network. Ideally I want to use it to connect IoT devices and regulate them through iptables.
Is it possible to connect my Pi to one WiFi network and act as an access point for another without using a WiFi dongle? If so, how do I do it?