The Airtable Community will undergo scheduled maintenance on September 17 from 10:00 PM PST to 11:15 PM PST. During this period, you may experience temporary disruptions. We apologize for any inconvenience and appreciate your understanding.
If you should only choose one of the options 1 time, you could create a view in your source table, with the condition that the linked record field is empty. Then, you can use that view to limit your possibilities in the linked field shown above. That way, you will only see the options that haven’t been linked to already.