I have a Plone instance which contains some structures which I need to copy to a new Plone instance (but much more which should not be copied). Those structures are document trees ("books" of Archetypes folders and documents) which use resources (e.g. images and animations, by UID) outside those trees (in a separate structure which of course contains lots of resources not needed by the ones which need to be copied).
I tried already to copy the whole data and delete the unneeded parts, but this takes very (!) long, so I'm looking for a better way.
Thus, the idea is to traverse my little forest of document trees and transfer them and the resources they need (sparsely rebuilding that separate structure) to the new Plone instance. I have full access to both of them.
Is there a suggested way to accomplish this? Or should I export all of them, including the resources structure, and delete all unneeded stuff afterwards?