Disable submit button on Create Movement Request by Expression Builder

Hello Experts
We have a requirement to restrict Movement Request Transfer from "DEMO - OUT" subinventory to "FG" subinventory
The movement request should be created only from "DEMO - OUT" to "RETURN" subinventories
By below condition, I can disable the submit button
#{bindings.FromSubinventoryCode.inputValue == 'DEMO - OUT' && bindings.ToSubinventoryCode.inputValue == 'FG'}
but the issue is, when we change the header level details, those are not getting cascaded to line level.
Hence, we need to use the values from line level. Can you please help me how to get that line level subinventory details for disabling Submit button?

Regards, Binoj