Hello Kevin,

Please, take a look at following situation:

My setup: "Corporate Stores Editors" group should be able to add/edit/delete info only in Corporate Stores category and related subcategories. Categories are public. 

By default, all users in "Corporate Stores Editors" have a WP Role as Subscriber. That because if they are Contibutor/Author etc role, they will see all website categories, which is not ok.We have overall more than 600 categories and subcategories, so any filter is more than welcome for editors.

My question: how can i display "Add new" button (or link) in admin bar for subscribers? Or there is another way to have this button/link and also keep categories filtered for this Role Scoper group?

Thank you

Just use Role > Categories to give desired users or groups a Category Role of "Post Editor" in the desired categories. In my WP 3.2 test installation, this causes "Add New" to appear in the admin bar for those users.