Aperture and Photo

You can't. Once you open the Library with Photos it creates its own version. Thereafter, changes made with Photos will not be visible in Aperture and vice versa. They're quite independent after the migration.

You could add the option "Add to Aperture" in Photos to the Share menu (System Preferences > Extensions > Share).

After you restart Photos and Aperture you will the option "Add to Aperture" in the Share menu.

However, this will share the edited versions, not the high resolution originals to Aperture.