How in Google Sheets to make it so that from the drop Down menu, you can select an item so that it repeats no more than 2 times in a range?

Question

Google Sheets

How in Google Sheets to make it so that from the drop down menu, you can select an item so that it repeats no more than 2 times in a range?
There is a document in which there is a graph, you need to be able to select your name from the drop down menu but no more than 2 times in the range