Will be hard to source - the point of the switch is to disconnect internal batteries when external power is provided - typically for when there's a set of alkaline cells in a piece of equipment.
Certainly such a thing would be available as a custom order, but I doubt its readily available.
I have a circuit with a NodeMCU on it and an RF Transmitter. I want the optionality to power the whole thing via either microusb on NodeMCU or via barrel.
If I power via microusb, I need to connect power and gnd from transmitter to nodemcu.
If I power via barrel, I want to connect both nodemcu and transmitter to the barrel directly.
I was thinking that the power loop between barrel and transmitter should be switched off (i.e. broken) if no pin is inserted. But I guess maybe it doesn't matter since no pin will be inserted and the loop will not affect the power coming from the nodemcu to transmitter?
Perhaps a diagram would be clearer - or maybe two for the different power options? Many Arduino boards
have a switching circuit on them for automatically switching from Barrel/Vin to USB and back, this might
be a suitable approach for your case.
Like I said, Vin will contain a voltage when USB is used