filing chapter 7 to include 2d & 3d mortgages but not 1st

I spoke to someone recently who lives in california. says he owes 400k on 1st, 100k on 2nd and 40k on 3rd mtg. He says he recently filed chapter 7 and included the 2nd and 3rd but not the 1st. He is under the impression he can continue to live there and just make payments on 1st and not the 2nd or 3rd. I’ve never heard of this before. Please someone confirm with me that this can be done