How can I change the view permissions in the admin CMS so that logged in users can only see their pages listed in the CMS Site Content section and not those created by other groups ?

At the moment, changing "Access" permissions for each page/directory allows Group1 for example to hide the directories/pages from the public (or from Group2). But, although Group1's pages/directories are greyed out in the CMS and the page content is not viewable/editable, the page title and information can be seen by other logged in users. This causes a problem if I have 1,000 groups (figuratively speaking) each with their own directory/page being listed in the Site Content pane.

Additionally, when a user sets permissions for their page, they can also see the ID of other groups (and can assign permissions to them). I don't want each group to see who else is on the site. Is there a way of assigning the permissions for pages (and their children) to a group so that the users don't have to do this?