How can I exchange chromosome of a GA generation with another GA

I am developing two GAs, the result of each iteration (or generation) of the first GA is used to compute the fitness of the second GA. Also, the first GA gets feedback from the second GA to rank its chromosomes. How do I automate the process so that the first GA would wait after the first generation for the second GA to use the chromosomes and give feedback to the first GA before the first GA could proceed to the second generation. Any help please?