Someone may post other fuller answers, but in the meantime, there are some previous discussions -- which is not to discourage more questions, data, or debate. I see answers to various questions: Whom did Hitler designate as his successor(s)? Did Hitler make them responsible for surrendering? Who did surrender?

"Why was admiral Dönitz Hitlers' successor and not some long time party member?" at https://www.reddit.com/r/AskHistorians/comments/4mi36u/why_was_admiral_d%C3%B6nitz_hitlers_successor_and_not/ : /u/OpenOb covered the governmental succession, and /u/Joltie covered who handled the surrender.

As for whether Hitler made them responsible for surrendering, /u/mikeman12312 had an interesting reply at https://www.reddit.com/r/AskHistorians/comments/2iehiv/did_hitler_designate_a_successor_in_the_event_he/cl1nl6l/