OIE - Custion optional rule Mileage policy

Hi all.

I would like to add a new (custom) optional rule in the Mileage Policy in OIE.

Is this possible? And yes, how do I do this.

Example:

Usage Car

Reason 1

Reason 2

Reason 3

User should only be able to pick 1. These 3 reasons have different rates.

I first used additional mileage but that does not work, when checking all the boxes you get all the rates accumulated.

Of course, good auditing helps but I would like to prevent this and only enable 1 choise per expense line.

Tanks all!

Irene