Dear Khon Trieu,
Yesterday, I got fzf via Homebrew.
I am going to learn how to use it a bit.
You use Linux commands like grep to collect all org-mode headings in multiple org-mode text files into one place and feed into fzf for search/query.
How about
[[Searching for a note across several folders and or files (XQuery + Keyboard Maestro) - External Scripting of Tinderbox - Tinderbox Forum]]