Hi Helena and Stanislaw,
I am afraid that, unlike the KudoZ leaders board, which has been created to provide information on KudoZ point holders in general, the purpose of "My directory ranking" is to provide information on the individual position being occupied in the directory and the number of KudoZ points needed to reach a better position.
For this reason, adding a list of other site members would not fit the purpose of the "My directory ranking" feature as it would no longer be focused on individual users but on a group of them in a given language pair and field, just as the directory.
Hope this clarifies.
Have an excellent week start!
I agree with Lucia.