How can I hide data element (and field) from the follow up form and the form archive?

Process Design Form Designer
2

Hello Marina,

I think you can hide field after send button click.

For this solution, you need to add an event on submit button click.
There is an example here : Form designer: How to add custom code on the submitButton event in the ASP.NET server side code-behind?

Example of result :

protected void Page_Load(object sender, EventArgs e) 
{ 
    base.Page_Load(sender, e); 
    submitButton.Click += new EventHandler(HideFields); 
	saveAsDraftButton.Click += new EventHandler(HideFields); 
} 

protected void HideFields(object sender, EventArgs e) 
{ 
	FIELD_TO_HIDE.Visible = false;
    this.SaveFormData(this.FormData, true); 
    SubmitToWorkflow(); 
}