Create a custom column as Column build from other columns (see attachments)
Lookup name: pathfilename
Column heading: Pfad&DateinameAll
Column type: Column build from other columns
Template: {:'formats_paths()'}
Remark: Prints all file names in case there exists more then one file record for a book. Downside: Delays Calibre startup a little bit. I usually hide those kind of columns in the library view (w/o check mark for the column, see column #31) and show them only in the book details window as you can see in first picture attached.
You can now use this newly created column where ever you want, e.g. in the book details panel or with Catalog like shown in picture two and three
Depending on for what you want to use it for this it is one possible solution. But Kovids solution is much better suited if you want to use the .csv file for further processing.