PSA Role Price Discount

I have finally been upgrades to V9, and so far so good, I use Dynamics mostly por PSA quoting and estimating, and I'm currently trying to setup this sort of discount to role prices:

However I don't have the Discount List field or is it available on the Role Price edit form:

How best to apply a discount based on resource hours to a quote?

Thank you so much,

Cheers,

P.