This is saved in the user profile and implicitly reloaded when you start any application of the suite. I don’t know exactly which directories and files are involved in the user profile and I don’t recommend fiddling with them.
If your concern is to set the same configuration on several computers for training, try copying your user profile to the other computers. Experiment with one “remote” comp but save the original profile first in case something goes wrong.
You can find the location of the user profile in Tools
>Options
, LibreOffice
>Paths
. On my Linux box, this is something like /home//.config/libreoffice/4/user/.