Hi

The source of information for each release is your readiness guides on the site or app

https://www.oracle.com/webfolder/technetwork/tutorials/tutorial/readiness/home/index.html

The list of analytics and reports are here.

So this tells you if some content is added or removed. It wont tell you if something was updated.

For HCM https://www.oracle.com/docs/tech/hcm-reports.xls

To understand what a dashboard does you do not need a technical design document. Just edit the dashboard pages then open the analysis and prompts to understand . It is pretty much self documenting. Just go to the advanced tab to read the logical SQL to see what it does.

For further information on a subject area read the user guides.

https://docs.oracle.com/en/cloud/saas/human-resources/24b/faohb/index.html

And then go to page manage sessions to view log to understand the data lineage to the application database tables and views in the physical SQL. Sometimes the calculations are here inside the metadata repository database (RPD). Ok so now you have the design of your content all the way from source to target!

https://community.oracle.com/customerconnect/discussion/40249/hcm-otbi-subject-areas-to-database-lineage-mapping-spreadsheet/p1