Beta 25 introduces Selective Export, which allows you to export certain types of hands rather than your whole database.
You can export certain dates, sites, or limits (cash) or table types, tourney types, buy-ins (tournament).
To open the Selective Export window use the PT3 menu Database -> Database Management.
On the Database Management window, select the database you want to export from, and click the Export... button.
This will open the Selective Export window.
Here you can select which hands you want to export.
You can select a specifc date, or range of dates; one or more sites; or Limits.
Once you have selected what you want to export, click the Export Hands button.
If you don't select any options then all hands will be exported.
If you don't select any sites, for instance, then all sites will be exported.
If you click the Tournament Hands tab you can select which tournament hands to export.
When you click Export Hands you will be able to select where to export the hands to.
A subfolder will be created for each site, which will contain the files containing the hand histories.