Have the people played different roles in this group? For example, was one the leader who started to hurt you and perhaps encouraged others to join? If so, you probably should forgive one at a time. I would recommend that you rate the degree of hurt that each person gave to you and start with the one who hurt you the least. Once you think you have completed the forgiveness process with that person, move up the list to the next person. Eventually, you will reach the one who has hurt you the most and you will be well-practiced in the process of forgiveness.
Learn more at How to Forgive.
Yes, and this is sometimes called group forgiveness. Group forgiveness is different from one person forgiving another. In the latter, a person can change feeling, thoughts, and behaviors toward an offending other. Groups do not have feeling and thoughts (individuals within groups have the feeling and thoughts). So, only actions are part of group forgiveness such as proclamations of forgiveness or establishing norms within the group to try to be kind toward the other group as justice is pursued.
Here is the abstract of a journal article on this issue:
Enright, R.D., Lee, Y.R., Hirshberg, M.J., Litts, B.K., Schirmer, E.B., Irwin, A.J., Klatt, J., Hunt, J., & Song, J.Y. (2016). Examining group forgiveness: Conceptual and empirical issues. Peace and Conflict: Journal of Peace Psychology, 22, 153-162.