I wire variable resistance

First off I’m a total newb to this site and to arduino products or builds but I am a very quick study and I have more then a basic understanding. I have need for a particular solution. Here is the rundown:
I have been converting the electronics on a vehicle. Taking an older model vehicle and modifying a newer model dash and steering switches to operate the older components. To make this all work I basically built different types of converters to allow the newer switches to perform and function as the factory intended and once the converter got that signal it sent out the signal the older vehicle’s wiring was designed to receive for XY function to engage. Now I have got to something that I cannot solve with simple relays or flip flop circuits and I need help.
I need a device that can take a 1 wire input and based solely on the resistance sent through that input the device needs to emit 1 of 5 different levels of resistance to 1 of 2 wires based on the input resistance it received. I will follow this with schematics on the output now. It should emit resistance to operate the following cruise control functions.

The following schematic is the input for the device. 1 wire, 5 different resistance levels based on button pus

I distill your request down to this:

I need a device that can take a 1 wire input and based solely on the resistance sent through that input the device needs to emit 1 of 5 different levels of resistance to 1 of 2 wires based on the input resistance it received.

That statement makes zero sense to me. From the schematic you posted, I can see how five switches can present six different resistance values across the BN and YE wires.

0R   Off
300R Set1
600R Set2
1K11 Resume
2K11 On
4K31 All switches open

Recreating those values is trivial, it's just resistors and standard values to boot. To clairify, are you replacing the five switches and keeping the original cruse control? Is so, what do the new switches look like. I'm just failing to understand what has you stuck.

what do you want the car to do when what happens. Leave out how you think the circuit is working.

You can output resistance from an Arduino using a digitally-controlled potentiometer. It probably isn't necessary. The receiver unit is powering this wire with a fixed resistance and it's measuring voltage. You could give it the same input voltages to get the same result.