If you run tshark -G folders, you'll see the location expected for the Personal Lua Plugins. Try locating your Lua plugins in that folder instead.
Alternatively, you can load a Lua plugin on the command-line using tshark's -X lua_script:lua_script_filename option, in which case the location of the Lua script can be anywhere you choose as long as you specify the full path to the file in the option.