I often wondered how the SQL-Select-Statement of a Query in WebUI looks like. For this you could use the SQL-trace of transactions ST01 or ST05. Alternatively you could put a breakpoint in class CL_CRM_REPORT_ACC_DYNAMIC method DATABASE_ACCESS.
Situation: You have some kind of business query in WebUI and you wonder how the SQL_Select-Statement is
Step 1: You put a break-point in the mentionned method
Here you see the From- and Where-statements.
Step 1a: Add a dynamic break-point for select-statements by pressing F9
Of course this will give you much more positions in coding.
Good luck when investigating.