Multi-step, live updating search


I’m creating a website and want to set up a multi-step (live) filter for searching companies, industries etc and now I’m starting to explain…

I have 3 categories. First category has 5 criterias. When you choose one of them (it should be possible to choose ONLY one in the first stage) there are more criterias on the first sub-category and when you choose one criteria from the first sub-category (also should be possible to choose ONLY one) there comes the second sub-category where you can choose more criterias. It would be the best if you get the results LIVE. I’m searching for days and still can’t find anything. Hope it’s understandable and someone can help me. Thanks