In addition to setting a person's access rights, you can further limit the data they see for connections, person notes, groups, and safeguards. For example, a person may have access to see all notes on a person's profile. However, if you add a limit for one or more note types, they will only be able to see those notes.
To restrict the type of data a person can see, go to the person's profile and manage their permissions. In the popup that appears, click on the "Limits" tab.
For each of these sections, ff "Limit access?" is set to No, the user will have access to all records in that section. If set to Yes, they will be restricted to only types that are checked.