I'd encourage you to look at the "SAP HANA SQL and System Views Reference" found at help.sap.com/hana_appliance - you'll find lots of useful system tables and views!
That being said, the specific table (or view, I forget) you're looking for is called OBJECT_DEPENDENCIES.
If you want to use it to find artifacts tied to scripted CalcViews, it can be slightly tricky... won't bother confusing you with the details unless this is your scenario..
Finally - a "hack" that many people would benefit from - turn on SQL Trace (if you know what you're doing) before navigating to the perspective/view/tab that you're using in HANA Studio that you want to investigate. After opening up the respective tab, turn off the SQL Trace, open the trace file - and dig around for a bit and you'll likely find useful SQL (or MDX) that the HANA Studio generates. In your case, you'd likely see SQL that HANA Studio generated to query OBJECT_DEPENDENCIES when you view the "Where-Used" tab.