Responses
It might be similar to the Voice or X factor where each group/entertainment company is going against each other and depending on the votes and (productions preferences) they might make a final group that will debut. Being affiliated with different companies or under the one that they prefer to sign with? Who knows but either way it sounds fun!
i'm thinking it's something like a survival show where the final contestants will form the debut group from diff companies! try searching the produce series (pd101, pdx101, pd48) of survival shows as reference
what's the purpose of this joint audition, each group battling each other or will they filter and combined girls regardless of their affiliation to make one ultimate girl group? So the group will be managed by three agency at once