You should be able to use a GridSplitter and place two TabControls on either side. Then the user could select one tab from each.
If you mean you want to be able to pick two tabs from the same TabControl and see them both, I don't think there's a standard control for that but you can probably get that effect through code somehow. For example, instead of a TabControl you could use buttons. When you click a button, the program could move the detail information for the button into a viewing area for the user to look at it.