Yes- any part that I played in the dynamics of a relationship is mine to own. The BB instructs us to make amends to anyone we have harmed, including ourselves (that's something worth really pondering as at first it sounds counter-intuitive), except where to do so would injure the other party. IME and IMO, when I look(ed) closely at almost every single person/relationship/situation, I had to own a part. There are some exceptions where the person was the sole one who did harm (here I think of something like rape), and I must compartmentalize that in a different place than I do the amends made.
Hope that helps.