For the analytics teams that you mention, and in general, you will hace specific assesments (coding, etc.) + business cases with a strong analytics component in them.
For getting better at analytic cases, on top of lots of practice, I would recommend you GMAT exercises.
There are free exams in the internet that you can use for practice (the one of LBS MBA page, Verits prep, as well as some free trials for courses such as the one of The Economist (https://gmat.economist.com/)
Hope it helps!