Simone, you may create an additional Account type and select the different profile questions for it.  And if while searching you choose a certain Account type, you will see only those profile questions that had been set for this type.
You can find more information about profile questions here: https://docs.oxwall.org/user-manual:users:profile-questions .
Otherwise this is considered as a custom code modification.

If you are not familiar with the code modification or plugin development, it would be better for you to find a developer who can help you. You can do it here: http://www.oxwall.org/market/specialists .