Creating New Group with an open dialogue box

Your welcome!

I was originally going to suggest a script, then assigning a keyboard shortcut to the script, until I realised that it was possible to directly assign the keyboard shortcut without a script! 🙂

Here is the redundant script, just in case it is needed for use in another script...

newGroupDialog();

function newGroupDialog() {
	var s2t = function (s) {
		return app.stringIDToTypeID(s);
	};
	var descriptor = new ActionDescriptor();
	var reference = new ActionReference();
	reference.putEnumerated( s2t( "menuItemClass" ), s2t( "menuItemType" ), s2t( "layerSection" ));
	descriptor.putReference( s2t( "null" ), reference );
	executeAction( s2t( "select" ), descriptor, DialogModes.NO );
}

The menu command can also be inserted into an action.