Transfer of suit

Dear All , Divorce case filed by applicant wife got dismissed by 'Family Court A' after hearing both parties. It took 2 years . No appeal was done nor was it challenged in high court. Now wife applicant has filed nullity of marriage in ' Family Court B '. The cause of action in both cases is same so it's clear case of res judicata. As 'Family Court A ' knows all facts I want to transfer new case filed by applicant wife for nullity of marriage to 'Family Court A' from 'Family Court B'. Matter still not started in 'Family Court B' Which Cpc Section to be used and if possible grounds for transfer.