In 3.9, you have a different 'cascade' of elements... adapters associate with networks, networks have muxes, muxes have services, services are mapped to channels. It makes a many-to-many relationship much easier, e.g. if an adapter can receive more than one network.
Anyway, you're on the right lines: you need to add a network of the right type (DVB-T, DVB-S, etc.) and then tell it what muxes there are on that network. It's that last step that corresponds to the 3.4 regional settings: you can select "Astra 28.2E" or "German: Bremen" from the
Pre-defined Muxes dropdown that appears once you've selected your network type.