You answered in the same minute I wrote my other post.
Of course Mr. Cooper (Nationstar Mortgage LLC, d/b/a Mr. Cooper) [which is the brand] has a parent, namely Mr. Cooper Group, Inc. (COOP), formerly WMIH. But this COOP, formerly WMIH has no other parent. Mr. Cooper Group, Inc. is the holding company, holding Mr. Cooper (Nationstar Mortgage LLC, d/b/a Mr. Cooper) and WMMRC in runoff mode. The same Mr. Cooper Group, Inc., COOP, has the same LEI as WMIH had, because it is the same entity.