Not kneeling, but getting the national anthem booed is a regular occurrence here in Spain, it happens pretty much every time a Basque or Catalan team gets to play the finals of the "King's Cup". Which given that FC Barcelona is generally the best or 2nd best team in Spain, tends to happen quite often. Bonus points if both a Basque and a Catalan team get to play. In this video there are several booing incidents, including comments from politicians from all sides (in Spanish):
To be fair, American sports have a lot more opportunities to get their national anthem kneeled given it is played in literally every match if I understand correctly, while here in Spain only the finals of the "King's Cup" and matches from the national team get the national anthem; but not literally every match.