How to get result for duplicate value with lookup ?

How to get the best result to a duplicate value with lookup? Our technical experts would explain you

I have multiple data with duplicate value. I want to lookup on these locums to get all data.
For ex. In column A1 it contains 8080 and B1 contains Yes, same happens to column A2 that contains 8080 and B1 containing No. How to lookup to get both data in column D?