I think you are looking to get down to the object (dimension, detail or measure) within a universe and which reports use them. If that is correct, I would like to know how to do this too. However, I don't think it is possible. I suppose there may be some third-party tools that provide this functionality.
If you just want to know which universe are being used in which reports, then Andreas is correct. You could also do a Query Builder query, but that is more complicated.
Noel