Another way to ask the question: "Can a field group be used in more than one custom post type (CPT)?" I basically have a one-to-many relationship (e.g., TypeA CPT can have multiple associated TypeB CPTs). I've created a custom field group called Implementation with a set of fields. I'd like to use the same group (Implementation) with both CPTs. Can I do that or do I need to create a separate custome field group for the child CPT?
1. Is there a way to use the same custom field in several groups?
Yes, you can use the same custom fields in many groups (field ID, field type, other settings ...) but one field group has to be registered in one CPT only. Because if the page has two fields with the same ID, only one will be saved value to the database.