InfoPath Dev

 Hello, I try to set multiple value of a checkbox based on previous choices. Example :
I have 2 checkbox columns :
Department : IT, Marketing, Admin
Application : A,B,C,D.
When I choose IT, I would like the application to select automatically A and B.

What I've done for now is as attachment. Unfortunately it only selects the last action. How to do a "AND" ?

I don't know if the question is understandable,
Please ask if you don't understand.

Thanks in advance !

This is not possible with rules - here's why: The multi-select control is bound to a repeating field. When you select an option in the control, InfoPath adds another instance of the repeating field. When you deselect, InfoPath deletes that instance - select a few items and take a look at the XML in a text editor & you'll see what I mean. InfoPath doesn't support inserting instances of a repeating element via rules - so what is happening is your rule is setting the default blank instance to A, then setting it to B.

Thanks for your answer ! Is there another way to do it thanks to infopath 2013 ?