This procedure is located under the Printers / Users menu in the Global Settings module. On the left side under Select user you select for which user you wish to configure the settings. On the right side under Select suppliers that will be excluded from preview you select for which supplier/suppliers you wish to configure exceptions. You can configure preview access for a group which means that all users that belong to a certain group will have the same settings.
The Preview Access per Supplier window.
In order to facilitate the registration of access rights for numerous user you can use the function Save as under the File menu.