Hello We have about 5 Tab across the top for different sites, Then within one site we have 5 document library. I set up a group in active Directory to view these Document library from settings Permission for this document library that where I add the AD group to have Read Access. The probelm is The users can't see the Tab(site). In Permissions for the Tab(site) I add The AD group to have limited access. still can see the Tab. I want these users look at the doucment libraty within the Tab(site)

If you want these AD group members to see all 5 libraries from this Site (tab) you really don't want to add them to the individual libraries. All you want is - permission the group at the site level. All the document libraries should inherit permission from the site. You permission from 'Site Permissions' page and make sure you don't add the AD group into any SharePoint group (i.e. permission them directly). My experience says AD groups within a SharePoint group does not work well. This should allow members of the site to access this site and all it's libraries. Hope this helps! BlueSky2010