Add navigationcontroller to detail view in splitview

I am following this example: http://doronkatz.com/ipad-programming-tutorial-hello-world. This example works great.

Now i want 3 tabs in the splitview and for each tab a new navigationcontroller. But i don't know how to implement it. I go to this code:

- (void)setDetailItem:(id)newDetailItem {
if (detailItem != newDetailItem) {
    [detailItem release];
    detailItem = [newDetailItem retain];

    // Update the view.
    navigationBar.topItem.title = detailItem;

    if ([detailItem isEqualToString:@"Test"]) {
        TestViewController *testViewController = [[TestViewController alloc] initWithNibName:@"TestView" bundle:nil];
        [self.navigationController pushViewController:testViewController animated:NO];
        [mapViewController release];

    }
    if ([detailItem isEqualToString:@"Test2"]) {

    }

}

if (popoverController != nil) {
    [popoverController dismissPopoverAnimated:YES];
}        

But i know that i actually don't have to use 'pushviewcontroller', i just want a new navigationcontroller starting from that point, and so for each tab in the splitview. How can i accomplish this? I know it's really basic, but i cant figure it out.

Thanks.