For example if you want to hide rooms for Land type of property type, you can do this very easy with depended fields:
Admin->real estates->depended fields->Add->Select property type “Land”, check wanted fields like rooms and save
Dependent fields ONLY CAN HIDE (NEVER SHOW) fields below it, but if you have another depended field below then it will NOT show hidden fields from previous depended field again if you didn’t select check-box.
So you should organize fields in this way. Sometimes you should add some additional fields for specific cases.
Also additional details: http://iwinter.com.hr/support/?p=7057