How do you mean Experience should be shown like in Warband? Are you reffering to the WB post-battle screen?
Considering it is a compleatly different XP-system in Bannerlord(where you get no general XP but instead need a number a skill-rank-ups to level up), I´d say it´s quite close. Hover the "upgrade"-symbol, after your name, and you can see what skills you ranked up in during last battle. However, you need to go to the charachter-screen to see how far from level up you are. The main difference though is that you have a lot of skills and can level quite easely without battles, if you don't want to create a warrior