Recovering addressbook

Nextcloud version (eg, 20.0.5): 23.0.12
Operating system and version (eg, Ubuntu 20.04): Debian 10
Apache or nginx version (eg, Apache 2.4.25):
PHP version (eg, 7.4): 7.3.31

I accidentially deleted an addressbook with many contacts. In the backup I have the nextcloud directory /var/www/nextcloud and mysql directory /var/lib/mysql.

Is there a good way to extract the addressbook out of these data, then I would just reimport the addressbook through kaddressbook.

The requested logs do not apply in this case, thus I omit them to keep the request short. If something is missing, please let me know, I am happy to provide it :-).