Can I restrict access to a particular folder in the team database?

Access is not managed by folder but, rather, for each individual document.

In the Document section of the database, you can mark each individual document with an access of Private and then list the people you want to be able to read and/or edit the document. If the people you want to allow access to are set up in a Notes group, you can simply enter the group name in the access field. All of the people in that group, of course, will need to be set up in the access control list (ACL) as having some kind of access to the database itself.

Step 1: Click on the access tab in the document:

Step 2: Click on the Private button



Step 3: Add the names of individuals or groups that can access the document (Readers can read-only, Authors can read and edit)