Hi @ara.ramirezg
Welcome to the ODK forum. We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a picture as your avatar because it helps build community!
SurveyCTO is based on ODK so when it comes to building forms it doesn't matter that it's SurveyCTO. You didn't attach your form so I can't test it but I think what you want to achieve is possible. I have this sample form which has not(selected()) function with additional conditions:
choice-filter2.xlsx (7.3 KB)
Let us know if this solves your problem. If not please attach your form and add more detaisl.