Did you figure it out or still need help? I just followed mcarlton00 instructions.
Example:
Path on Jellyfin SERVER for my movies library
My path replacements:
I worked it out, I believe, through asking on the GIT, and determining that for my setup I don't actually need to add anything to manage path replacement. Since all my media is on my LAN through accessible shares and my JF server sees the same shares that my Kodi clients will see MPR doesn't actually do anything. Well accept confuse me ha! But I've left the MPR fields blank and so far haven't had any issues now that things are setup. All my trailers and extras function as expected as well.
JF Wish List:
IMDb Top250 metadata
Collection content rules: Library-Title/Sorttitle/Tag/Director/Filename/Contains
Collection organized by Library
Collections scanned to editable XML
Media info show added Collection
Soundtrack auto link to movie by title/sort/Manual
Read Music Album Sort