I have two lists, Main and SourceData. SourceData contains a column named SerialNum with list of unique items (serial numbers in this example). Main contains multiple columns, one of which is a lookup column connected to SourceData's SerialNum column.
Here's my requirement: I need to show only items that are unique among BOTH lists in the user drop-down selection box on the Nintex form (i.e. remove items from the drop-down that are already in the list named Main). Second, I would prefer to do this using Nintex forms and javascript (if required) vs a workflow. Thoughts?