Your question is not clear to me. Would you like to show or hide fields in Contact Form 7 based on a users action?
Please explain your problem into detail. If others here are able to understand your actual problem, they may be able and willing to offer a possible solution.
This would be a good answer.
I use hidden fields on my forms for spam control. If hidden field is filled out then form is not sent. Only robots can see them, so it has to be spam.
You can add any HTML you want, including any standard HTML form elements, in the form section of the CF7 interface.
In your case you could add something like:
<input type="hidden" name="my-hidden" value="hidden-value">
@mjancosek1: There is a plugin Contact Form 7 Honeypot for a similar spam control feature.
