I'd like to be able to choose only one player (or more) games in the Opening Exploler, not only whole lichess :-)
I would help ya out to the best of my ability but I don't understand the question.
The opening explorer purpose is to show moves from good players that one would not have considered.
Your idea is that you want to able to study the opening repertory of a certain opponent.
What does X respond in this position? Is that right?
I wish there was such option in the advanced search.