I just read a couple articles about folding in https://www.scintilla.org/ScintillaDoc.html, in particular https://www.scintilla.org/Lexer.txt, and I see that my notion of "level" in the 1st comment agrees "fold level" scintilla and lexers uses internally to give each line. So then the command to move to parent of comment node could be stated as: * **C1**: Find Ist line above current line, that has a fold level smaller than of current line, and is a fold point. If exists, move cursor there.
@intact In the initial version of the post I suggested a command that combined moving to parent node and folding that, and an opposite command that unfolds a parent node and moves to Ist child node. But for modularity, perhaps better/simpler to implement just the main missing part, C1, and then the combined ones could be made from C1, existing toggle and moving with keyes, with macros or other ways, I guess.