in my form I am saving employee name + applicable period + applicable year + type of action as the title via a calculated column. if any of the information is changed, it would create a new item instead of updating the current one.
I know InfoPath does this, any idea how to do this with Nintex forms? I've set the list to set title for unique values but that does not help.
When you use a form on top of a list item, it relates directly to that underlying list item. Therefore any modifications you make to the form will simply add to the existing item (and not a new separate item). You could maybe use a workflow start form and have it create new items each time that it is used by using a workflow and the create item action. Using a workflow in this way would probably get you as close as possible, but you won't find the exact functionality that you require out of the box.