The Oracle Enterprise Repository (for Fusion Applications Cloud) website is stand alone catalogue of technical information about Oracle’s Application products and contains detailed information about Fusion Application schema tables, web services, Analytics Reports and Migration/Import templates.
To access the website click here: https://fusionappsoer.oracle.com/oer/
Link to information about business questions and answers for Oracle Transactional Business Intelligence (OTBI) Embedded Analytics Cloud, HCM Subject areas: http://www.oracle.com/technetwork/documentation/otbi-hcm-2225528.html
And for OTBI-E subject areas. The advantage of this is, that it is indeed very similar to Oracle BI Applications (OBIA) and can easily be applied for the same: