On the Customize page you can override the main backup filter. It will show a tree with all selected sources for the backup job.
The customized filter can be defined only for folders. That is why add button is not enabled for files.
Any customized filter completely replaces the main filter. Once defined, the customized filter applies on the current folder and recursively on all its subfolders until another customized filter is met. The behavior is the same for include and exclude filters.
Suppose we have the folder structure in the picture above. Backup source is "D:\Backup sources". A main filter is defined to include all.txt and.doc files. Suppose we do not want to backup.txt files from "ccc" folder. For this we define a customized filter on "ccc" that includes only.doc files.
The result is that all.txt and.doc files will be included except the.txt files inside "ccc" folder as in the picture bellow:
When a folder is selected, the Add include and Add exclude buttons from the bottom are activated (these are activated only for folders, not for individual files). That means you can replace the main filter with a different one. The customized filter is valid only for the selected folder and its descendants. Click the Add include or Add exclude button to define the customized filter. This will open a Filter Properties window. You can define include or exclude filters in this window just as you do in the Filter page.
All files and folders for which a customized filter is applied are shown in red color. You can Edit, Copy or Delete a customized filter by selecting the folder and clicking one of the buttons bellow.