How to restore a whole directory from history of git repository?

try adding ‘–‘ between revisions and paths:

git checkout 348ce0aa02d3738e55ac9085080028b548e3d8d3 -- path/to/the/folder/ 

And if you want to recover a directory from the previous commit, you can replace the commit hash by HEAD~1, for example:

git checkout HEAD~1 -- path/to/the/folder/