Hi Joyce,
Unfortunately, there is not much documentation around the universe objects/classes themselves. Most of them are a bit self-explanatory by names. If you look into the properties of a given object, it'll give some information about the Select Statement or Where Clause its using, which inturn needs to be mapped manually by looking at the Logical data model.
There are some filters that might be referencing objects in classes, so you'd have to go look at the details of those objects to see what its really pulling.
Finally there's Derived Tables, which again have SDM logical name syntax associated to the tables/columns the table is created from.
This could be a great idea to be considered if there is good enough community demand on it.
_R