 Requirement:

Hide products with the Product Family "Software" when a Configuration Attribute is set to "Perpetual."

 Solution:

Use an Error Condition to evaluate the Product Family value on the Product Option record.

Configure a Product Action to Show all products except those with the Product Family "Software."

 Mechanism:

The Error Condition evaluates the Configuration Attribute's value against the Product Option.

The Product Action ensures visibility is dynamically controlled based on the evaluated condition.

 Salesforce CPQ Reference:

Error Conditions and Product Actions are key components of Product Rules in CPQ to implement dynamic product behavior ​.