You can create a custom column called "Already Read", of type "Yes/No", and manually toggle it for each book. Or add a tag "Already Read", and search for it.
The information has to come from
somewhere, and the Kindle does not store already_read info.

So it will have to be manual.
The Marvin ereader app for iOS, as an example, does store such info. And the Marvin XD plugin for calibre can export this among many other details from Marvin.