Viewing document library be people with permissions only on specific documents in the library

Hi all,

I have a problem that our SharePoint administrator is at loss to give a viable solution.

I have a document library with potentially a few hundred documents, most of which should only be read by two groups. However some 10% or so need to be read by others. I can easily give specific permissions per document, but these people are unable to access the document library, which they need to (specific views to make information accessible).

The only solution our SharePoint administrator could offer me was to give everyone read permission, and then downgrade the permissions when needed. But we are talking about a few hundred documents, and I am hoping that another solution exists.

We are using SharePoint 2013 on site.

Thank you,

Ofra