I'm using migrate_d2d to migrate my Drupal 6 site to Drupal 7. I've already created several working migration classes to migrate the content of the D6 site into the D7 site. Now I'm working on migrating the organic groups and the related user memberships. I've read that OG (i'm using 7.x-1.19) got a build in migrate routine. When I checked /admin/config/group/group-migrate, I hoped to see some settings where I could insert the data of my legacy database, my User Migration class, click a button and be done with it. :-D Unfortunately, that's not the case.
I have a hard time to find any documentation of how to use the migration functionality which comes with OG. Could anyone please give me a hint how one is supposed to migrate OG groups/memberships from a D6 database to a D7 database?