You refer to the period of time or the thing immediately before the one that you are talking about as the preceding one.
As we saw in the preceding chapter, groups can be powerful agents of socialization.
如我们在前一章所见,群体可以是社会化的有力动因。
She informed us that eighteen members of the staff had left during the preceding year.
她告知我们有18位教职工在此前的一年里离开了。