To add a new custom Backup Profile, click the + Create New Profile button.
Select the type of backup (Database only, Full (DB + Files), Themes Only, Plugins Only, Media Only and Custom files).
In the empty box, add a name for the backup profile.
Once you've added a name for the profile, you'll see the Backup Profile listed in the available Backup Profiles.
To edit the profile you created (or one of the existing profiles), click the gear symbol to the right of the profile.
Based on your Database only, Full (DB + Files), Themes Only, Plugins Only, Media Only or Custom files selection, you can customize options for database, files & directories and more.
To select files to exclude from your custom backup, uncheck the Use global defaults option.