France,Switzerland,Portugal and Spain are the Group leaders of the League A teams at the moment.
There are also teams in Leagues B,C and D who have played games.Teams from A,B and C can move downwards toward relegation to a lower League and teams from B,C and D can move upwards to a higher League if they top their groups.
Group D teams can’t go any lower.
They are at rock bottom.
It’s all very simple.