The default contains the `%d` wildcard, which is replaced by the directory. [This man page](https://www.mankier.com/1/xdg-open) says "Open the current directory in the default file explorer: `xdg-open .`", which implies you can give it a directory and it will open a file explorer program. It works on my Linux Mint anyway. (I did the cinnamon install and I don't have nautilus).
does it open that file or open the file manager at the path with the file selected[1](https://github.com/geany/geany/pull/3815#user-content-fn-1-d4169df4d23068cfe... In other words does xdg-open do the same thing?
xdg-open with a file (i.e. if the user changes `%d` to `%f`), opens the associated program for that file, it doesn't open the file manager. If the user wanted the file manager to select the file, they should change it to e.g. `nemo %f`, which works on my system.