In Org mode: How can I move point (up) to the current heading (or the first line under the heading)?
org-mode is built on top of
outline-mode, so you can use all the outline navigation commands. The one most relevant to your question will be
outline-previous-visible-heading. You should probably find a comfortable keybinding if you plan to use it a lot.
Note that there is also a non-interactive
org-back-to-heading that you could wrap in a command, if you like. Docstring says:
(org-back-to-heading &optional INVISIBLE-OK)
outline-back-to-heading, but provide a better error message.