So Sumar’s (Spanish party) politicians will apparently be distributed across both The Left and the Greens European parties. Presumably an image maneuver, since joining an European party usually doesn’t bind your vote, and Spanish green parties usually get integrated in leftist electoral options anyway.
Sumar is a mix of several parties, a coalition. Also, the first of the list is an independent person. Not all the parties compounding Sumar are integrated in the left or the greens. The first of the list, the independent one, will go to the left. Second and third on the list, will go to the greens, and the fourth one, from a party that is not integrated in the greens but in the left, will go to the left if elected. That is because Sumar is a coalition, several groups and parties got together for the elections. Representatives from each party can choose where group to go.