Hi,
I’m not sure if you follow the Pods project but in the upcoming 2.7 release, they’re adding a new field type called Flexible Relationships the field will allow you to create a related post type from with the parent record. The link to the announcement can be found here https://pods.io/2017/05/30/pods-2-7-beta I could really see this being useful in ACF.
**Side Note**
I’ve found a couple of extensions that can do this but it looks like it’s been a few years since they have been given any attention. There is also a paid add-on available at Code Canyon but I feel that this is a pretty fundamental element.
