A user, with SEARCH and VIEW permission to a Document Type, can be set to be able to access documents with specific Global Field Values only. This can be done using the 'Limiting Document Access by Field Value' feature.
Under 'Document-Properties' Settings:
Enable User-based Global Field for Limiting Document Access
When CHECKED, the Global Field selected is used to limit access to a specific Document Type matching the field values set in the User Page.
When UNCHECKED, there is no feature to limit access to a specific document based on the Global Field selected.
Hide Folders in the Folder Browser when there are no files within the folder viewable by the user (in v7.5.7233 and above).
When CHECKED, folders in the Folder Browser that do not contain document files that the user has access to will be hidden. When CHECKED decrease in performance in Content Central may be experienced.
When UNCHECKED, all folders in the Folder Browser will show regardless of the document contents. Some folder may appear empty if the document contents have global field values not accessible for the user through the Limiting Document Access Feature.
Under 'Limiting Document Access by Field Value' ...
When there 1 or more field values are CHECKED, the user is limited to access only the documents, that have field values matching field values CHECKED.
When there are no field values CHECKED, the user is not set to any limiting access. Therefore, the user will be able to access any document with any field values.
SEARCH and VIEW Document Type Permission apply. User(s) must have SEARCH and VIEW permission to the Document Type, to be able to apply the Limiting Document Access by Field Value.