Cascading with special Option "Don’t know/Refused" --- SOLVED :D

Dear All

Is it possible to sett cascading with special option ?

Q1 Multiple question
Option A
Option B
Option C

Q2 Single Answer
Option A
Option B
Option C
Don’t know/Refused

choice_filter at Q2 = selected(${Q1}, name)
How to sett Don’t know/Refused as a special option/ always show at Q2.

Thanks

Regards
Tulus

@tulus45, have you tried using the approach discussed previously? It should solve your issue: