>Hi,
>In my testing, SET RELATION TO works for me. The nested grid show the correct records. The only thing is, when I click on the nested grid, i cant select other child records anymore using mouse click. However, I still able to scroll to other child records using keyboard (Up/Down arrows)
>
>I changed my code to use SET FILTER TO statement, but still the same.
>
>Thank you

Then you have other code that interferes with the mouse.
use you LockScreen ?