Do you mean the old ‘progress bar’ in the kingdom name box?
Else I don’t understand the request, as power levels are shown with stars as before. Admittedly with a daft system of coloured stars that’s really unintuitive.
@xamax I think what you really want is in the image below. Register your account at http://gowdb.com and bask in the amazing world of what @Lyya has put together for GoW fans.
I had to look at some old map screens on Google image and have to say that I had no idea that there was actually a progress bar built into the kingdom name box.
When I was actively working on my kingdom power levels, I used an external spreadsheet to track my progress and calculate how many troops/levels/traits it would take to get to the next power level. The progress bar would give you a hint, but wouldn’t be that helpful overall in my view. With the way the formula steps down value after 10 troops/30 traits/200 levels, it just doesn’t convey enough information to actually inform decisions.