Using The Path Bar
The Path Bar, located at the top of a comparison, shows the full path of the files that are currently being compared.
Depending on available space and length of the path, some items may only be shown as icons. If there's not ebough space for that, a ··· button will host the parts of the path. Click that button to reveal those parts.
A and B
The files are marked as A or B. In Kaleidoscope, file A is by default considered the older of the two and file B the newer version. You can swap the A and B files with the button in the center of the view or via Edit > Swap A & B.
Actions
When you click on path bar item, a contextual menu appears with the following options:
Reveal in Finder
Opens the Finder with that directory selected.
Open in Terminal
Opens the Terminal application at that directory.
Copy Path
Copies the entire path to the folder to the clipboard.
The last component in the path represents the file. The contextual menu for the file item contains the following options:
Open With...
Allows you to open the file in an external application of your choice.
Reveal in Finder
Opens the Finder with the file selected.
Copy Path
Copies the entire file path to the clipboard.