How to publish a field value from the Contact to all linked CDO Records?

Hello,

We have a business use case where we need to publish a Contact field value (Last SFDC Campaign ID) to all linked CDO records within a single CDO. Ex) If john@test.com has 5 linked CDO records in a Custom Object, I need to take the field value that's currently in the field Last SFDC Campaign ID at the Contact Level, and I need to publish it to all 5 CDO records in a CDO field "Last SFDC Campaign ID". How can this be done?