Do you plan on moving over your users as well? That's where things get tricky as you're then dealing with migrating Joomla tables too. For CB it's just a matter of exporting tables prefixed with _comprofiler, _groupjive, and _cbsubs then importing them to your new database.

To move your Joomla users you need to also export and import _users, but that won't be up to date with Joomla 4 structure so you'll probably only want to export the data and not structure of _users. You'll also need _user_usergroup_map so they don't lose their usergroups and if you're using custom usergroups you'll also need _usergroups and _viewlevels.

Easiest approach is probably to make a clone of your site, upgrade it to Joomla 4, then move the database data to a new site so all the table structures and data will be up to date.