I\'m trying to create a sectioned NSTableView using NSArrayController and cocoa bindings. I\'m searching for a similar approach like with NSFetch         
        
Though NSTableView can render group rows, unfortunately it depends on the delegate or data source to flatten the hierarchy. It doesn't understand alternate data source semantics like UITableView's UITableViewStyleGrouped, nor does NSArrayController have equivalents to NSFetchedResultsController's section methods.
One option is NSOutlineView which is designed for displaying arbitrarily deep hierarchical data, but it probably creates more work than necessary for a simple two-level structure. (You can bind an outline view to NSTreeController but the tree controller is poorly documented, and to boot, it's badly designed.)
So, here's what I suggest:
NSTableViewDelegate and NSTableViewDataSource.YES from tableView:isGroupRow: on the section headings.You could also look for a reusable, bindings-capable controller from a third party.