Combining Reports From Different Subject Areas

I am new on reports creation. I have two questions:

(1) How can I combine fields available in different subject areas in one report?

For example, I have a Reporting (Real Time) report created using Opportunity Product Revenues subject area and one of its column is Estimated Close Date. I would like to get this date's equivalent Fiscal Year and Fiscal Month values.

I can see that still under Reporting (Real Time), there are Fiscal Month and Fiscal Year fields under the Opportunities subject area. How can I add these fields to my report under the Opportunity Product Revenues subject area?