Family Systems therapists view problems within the family as the result not of particular members' behaviors, but of the family's group dynamic. The family is seen as a complex system having its own language, roles, rules, beliefs, needs and patterns. The therapist helps each individual member understand how their childhood family operated, their role in that system, and how that experience has shaped their role in the current family. Therapists with the MFT credential are usually trained in Family Systems therapy.
Sourced from: https://www.psychologytoday.com/us?tr=Hdr_Brand