For plans, addons and charges there are options to define multiple price points as well as differential pricing in Product Catalog 2.0 whereas there are no such options for coupons. Especially when there is an existing coupon attached to some subscription but you want to change the discount amount/ duration/validity for new subscriptions then the clone coupon option is used.
You can clone the coupon by following the steps given below
Step 1: Go to Product Catalog -> Coupon
Step 2: Open the coupon to be cloned and click on the 'Clone coupon' button
Step 3: Enter the details of the coupon that needs to be edited and click on 'Save and create'. The cloned coupon is created.