You can use xfa.host.setFocus("Subform1.childsubform.textfield1"); to place focus on a textfield/object element inside subform but does anyone know how to setFocus on a subform?
I like using Doc.scroll because setFocus positions the field in the middle of the display area which I find can be confusing. If the user has clicked on something to go to a particular part of the form I think they would expect it to be at the top of the page.