Is it permissible for the nephew (son of the sister), who was not breastfed by the mother, to marry the daughter of the other sister, knowing that his elder brother was breastfed by the mother?

A man is permitted to marry his maternal aunt's daughter as long as he was not nursed by her grandmother. This is because only the one who was nursed by the grandmother becomes a maternal uncle to the girl. As for one who was not nursed, there is no prohibited degree of kinship between him and her.