I too am confused as to why the author has chosen to include their entire Bash configuration in this repository. As far as I can tell, this is the only interesting file:
I also wasted a fair amount of time looking through these files, trying to figure out what all the miscellaneous bash configs had to do with the stated purpose. I did find that there is a nice undocumented feature of the cdff command, which allows you to specify the directory of a window lower in the stack by sending a numeral as the positional parameter.
https://github.com/NapoleonWils0n/bashfinder/blob/master/.ba...
So you'd just want to rename this to something obvious like "osx-finder.bash" and source that file.