This theme isn’t well developed in terms of quantity, but the insights are important:
8. The whole Church, as a priestly people, acts in different ways in the work of reconciliation that has been entrusted to it by the Lord. Not only does the Church call sinners to repentance by preaching the word of God, but it also intercedes for them and helps penitents with a maternal care and solicitude to acknowledge and confess their sins and to obtain the mercy of God, who alone can forgive sins. Further, the Church becomes itself the instrument of the conversion and absolution of the penitent through the ministry entrusted by Christ to the apostles and their successors. [See Mt 18:18; Jn 20:23.]
The whole Church has a role in preaching the Word. The whole Church also intercedes–and I would interpret this as prayer and example. “Care” and “solicitude” are the words used here.
I would suggest the whole Church also serves as a receptor for the celebrants’ acts of penance–in part at least. Since we are urged to model ourselves on God’s way of forgiveness, it would seem the community is obliged to receive and accept whatever amends a penitent sinner offers it.