When I use search to find any thread from previous SCN space that currently is in archive I can see only question itself and maybe the answer marked as correct. But from my experience, very often this answer is rather useless without seeing the context.
I can't understand for now how can I use new platform for finding answers that I need.
You will have to click the title of the question you are interested in from Archive or Archive search. Once you open the archived question, you will be able to see the answers that were submitted. Also, please be advised that there has been a bug reported with searching archived discussions. We are currently working to to solve this issue and a fix should be implemented by the end of the week.