how to use per-recipient table

sorry for stupid me. I have read the document
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and I understand " you can't specify a lookup table on the
right-hand side of a Postfix access table. This is because Postfix
needs to open lookup tables ahead of time"

now I want to restrict users who can send to " ... at example dot com" belongs to:

3. smtp-auth users

how can I config it? I lost in configuration parameters.
thanks a lot for hint!!