Hi,
Based on my understanding of your scenario, If you are adding a TabControlwith several Tab Items to your Navigation Region, I believe you could try defining a different region in each of your Tab Items, this way you could registered eachView to its corresponding region in one of these Tab Items for example using theViewExport attribute approach.
On the other hand, if you are defining the region in your TabControl and you need to specify the order on how the views will appear in this region, I believe you could benefit of theViewSortHint attribute provided with Prism, which could also be used with theViewExport attribute. For more information about this you could check the following section of the documentation:
I hope you find this handy,
Agustin Adami
http://blogs.southworks.net/aadami