Hi @ch4rlie
I’m afraid there’s no tool to do it yet. What you can do is to create the new field group and then use the update_field() function to fill the newly created fields. This page should give you more idea about it: https://www.advancedcustomfields.com/resources/update_field/.
Please keep in mind that you need to use the field key to update the newly created fields.
I hope this helps 🙂