we have 2 accounts (local, group) of Adobe Experience Cloud - each including AAM. Will it be possible to create a destination between AAM local <-> AAM group in order to share segments between them?
You can use 1st way by your own to share data from one AAM instance to another & for 2nd & 3rd way you need to raise ticket to amsupport@adobe.com so that someone from AAM support team will reach out to you & setup accordingly.