Normally, if you are trying to locate a foreign key, you can proceed as follows.
1. Transaction Code: SE11
2. Enter the table in question.  For example BSEG
3. Select a table field. For example BUKRS or KUNNR
4. Click on Foreign Keys. The symbol or icon is a key with an arrow pointing down. It is before Srch Help.
5. A screen will pop-up with the foreign key fields and tables where you can see the CHECK TABLE.
 
Or 
1.  Enter table using SE11: GLPCT
2.  Select RTCUR
3.  Click on Foreign Keys
3.  In the pop-up screen,  double click on TCURC in the check table field.
You need not click for each field to know the foreign keys attached. You may goto the Entryhelp/check tab of the table and see the check table attached with the field. Left to that is the checkbox for foreign keys. Check table acts as the foreign key table in most of the scenarios. 
You can also click the Graphic button to display all the Foreign Keys in a single glance.


Serkan AKKAVAK
Computer Engineer
ABAP Developer & SAP MM SD Consultant
Contact : serkurumsal@yandex.com