I don’t you think can prepare for it as such. Group exercises are designed in a way that candidates shouldn’t be able to prepare and it is more about reacting to the situation you are presented with and adapting to the dynamics of the group.
Just go in with a willingness to collaborate with everyone else (don’t dominate proceedings), and try to be flexible/adaptable in your thinking and approach. Make sure you get your ideas forward, get consensus for those ideas from your group, and be supportive (where appropriate) of good ideas of other people.
General group exercise advice:
- Try not to be someone completely different to who you are
- Contribute
- There are lots of roles and responsibilities to take on - it doesn't matter what you do but find a way to contribute beyong adding your ideas
- Have an opinion
- Support each other
- Keep an eye on the time
- Try to come to a conclusion/judgement/outcomes