How to dynamically populate a field based on another field selection ?

Hello,

I’m trying to dynamically populate the value of an attribute (named “service”) based on a selected company. I attempted to use a displayCondition, which allowed me to retrieve the correct value, but I couldn’t actually set it in the “service” field.

Do you have any ideas on how to handle this scenario? At the moment, I’m using a compute rule that updates the value after the identity is created or modified, which means the service cannot be previewed before the operation is completed.

Thank you