Up-down bow
Appearance
Combining up and down bow over a single note can be done with a macro.
\version "2.24"
updownbow =
-\tweak parent-alignment-X #CENTER
^\markup \concat {
\musicglyph #"scripts.upbow"
\hspace #0.3 % tweak space to your liking
\musicglyph #"scripts.downbow"
}
{
c''1^\upbow
c''1^\downbow
c''1^\updownbow
}