How can I have the additional Field i created in Incident to be shown as well as option in Select Criteria in Service Catalog Business Rules?

I have business rules in Incidents module and i selected the Additional Field created as criteria and this is working fine.

Now i need to do the same rules for Service Catalog template but i cannot find the Additional Field created (used previously)

In the "incident additional field" the field i created is said to be 'common for both incident and service catalog'

Many thanks,

Vanessa