Union (Combine Unique)
Combine multiple lists into a single list of all of the unique values contained in any of the input lists. The lists can be of any type (text, number, object, and so forth) as long as all lists are set to the same type, including the output list.
List 1: The first list of items.
List 2: The second list of items.
(optional): you can define any number of input lists, of any name. They will be combined in order.
List Union: The output list.