Wire the selector switch to 6 digital inputs and its common terminal to GND. Use INPUT_PULLUP in the pinMode for the pins.
Read the 6 inputs to determine which one is currently LOW and use switch/case based on the selected input to run the required code to read the pot connected to an analogue input and change the parameters you require.
There will need to be some finesse in the code to prevent a parameter being changed when the pot position is read immediately after the switch position changed but you could deal with that by only reacting to the pot once it has been put near the previous position for the newly selected switch position.