How do I import only 1 occurrence without errors?


I have a DATA module with a line item named "Scenarios." I need to import this line item into a list also named Scenarios list. The data module is dimensionalized by a different list so I cannot use the isfirstoccurence() formula. What's the best practice when it comes to importing this line item into a list as to not have any errors pop up every time, I run the action? Right now, of the 1000s of line items, there's only about 10 unique values I need to import but I can't figure out how to set up a filter or which formula to use.