Torah Temimah cites Kerisos 26b.
These three “knowledge” phrases — regarding the individual, the nasi, and the community — for what purpose?
Diyuk / Ribbuy of repeated “hod’a” — each status independently requires that the sin become known to the relevant party.
The three separate statements of “when the sin is made known to him/them” teach that awareness is a prerequisite for every level of chatas: the ordinary individual, the nasi, and the community. One cannot borrow the awareness requirement from one category and apply it to another; each must be derived on its own terms. Consequently, until the relevant party actually becomes aware of the sin, the obligation to bring the chatas does not yet arise.