俱舍論頌疏論本 24.4

24.4

斷至五二向者，謂預流果進斷欲界一品修惑乃至五品，名一來向，趣一來果故。

As for 'Abandoning up to five is the candidate for the second': it means that when a stream-enterer progresses to abandon from one category up to five categories of the desire realm's defilements of cultivation, they are called a candidate for once-returner, because they are proceeding toward the fruit of once-returner.