@Davide_Z and @Davide_445 — I’m the product manager working on various projects in the content sharing space, including page/sub-doc sharing. Thank you for your request as we understand how cumbersome managing multiple projects across different people can be. Please do add your vote here and see our overall sharing roadmap here, that lays out the steps to your request and why we are not able to provide an ETA.
In addition to the option @Jasmine_B shared, what we’ve seen other customers do is keep all pages you want to share both internally and externally in the external doc, and then embed pages from the external doc in the primary doc. You’ll also share your external doc internally and externally, so people internally can access embeds from that doc in the primary doc.
Please continue sharing your feedback as we’re reading every post and incorporating your insights into our designs and sharing model updates.