How can I get the same fold button as workspace in form?

[Wei_ Ling]

Is there any chance of achieving the same effect in the background form?

[Mark Manders]

One of the OOB forms that has this, is the 'request clone' form. It's handles through a client script where the form section is 'Options'. You could try the same: 

function onLoad() {
	var sections = g_form.getSections();
	for( var i=0; i<sections.length; i++ ){
		if( !sections[i].textContent.startsWith("Options") )
			continue;

		// state is not closed
		if( (sections[i].className).indexOf('state-closed') != -1 )
			continue;

		hideReveal(sections[i].id.substr('section-'.length), false, true);
	}
}