Customer Contract: Hide the "Buy" intent contract types

Summary:

How to hide the "Buy" intent contract types for the Customer Contract Administrator?

Content (please ensure you mask any confidential information):

I'm creating a custom job role that can view Sales Contract (customer contract) by copying the standard Customer Contract Administrator job role, and removed some FSPs and child roles according to customer's security requirement. However, I notice that during Create Contract, the Contract Type always show both the Sell and Buy intent contract types.

As this is a Customer Contract role, the business requirement is to only be able to see the "Sell" intent contract types. How do I hide the Buy intent contract types?