SIR workspace dialog box on state is closed

[soumya17]

Hi , I created a custom field in SIR table and when state changes to close , based on close code value i want to populate in the form which i am able to do.

But in workspace view, when state changes to close a dialoge box appears (image)
I want to add the custom field and ui policy should work in dialogue box. how can i achieve
i tried to add in ui builder, i am able to add but choices are not showing (screenshot)
can someone help me how can i proceed.

Thanks