To modify who will see which category please do the following:

1. In database from back-end activate debug mode
2. In Settings>Users & Companies>Groups create specific set of groups for which you would like to display only relevant categories from Documents menu and add users if they exist

3. By exporting or checking metadata, get external ids of all the groups you will use to define the display views for each line in Documents section on the website
4. On the website as Administrator (not portal user) go into HTML editor and edit each ‘Show’ view as needed

From there you can decide and add the particular group you would like to display the ‘Show’ view to. You can add multiple ids of groups (separated by coma and no spaces) in case you would like to show for example ‘Quotations’ category to more than 1 group.

Line to modify:
Whatever group you add here, they will see the category and the ones removed won’t be able to see this category displayed under Documents section on the website.


IMPORTANT:
Update the standard view only from front-end website view in HTML editor and NOT from back-end Setting >Views.

If you do it from Settings, then Odoo will duplicate the view with introduced changes by you. As a result, when you would like to upgrade your database in the future, Odoo will update the original view (default one) and not the second one which was edited by you. The upgrade to newer version will encounter issues and you will loose the edited view.