You could probably achieve what you originally wanted with some custom PHP, but that’s out of my depth sorry so I can’t help you there.
I’ve not exported content from ACF before and I don’t think it’s possible by any normal methods but here’s where I would look if I wanted to do what you want to do;
As the fields are stored in the database, I would imagine you could move the content by editing the fields metadata in the database, essentially re-assigning where it belongs.
Sorry for the vague answer, it’s all I can think of to help you!
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