Updated: Dec 14, 2021
The role access is controlled by the sensitivity settings, which are bulk updated by going to the "Contact Categorisation" and "Note Categorisation" reference data tables. From there you can right click on a note type and click maintain.
For all notes/contacts of the selected type you can allow all roles to view, or click create to specify which roles should be able to view the data of that type. These settings can be updated at any time.