documentclass{article}
usepackage{amsmath}
usepackage{unicode-math}
usepackage{tikz-cd}

setmainfont{STIX Two Text}
setmathfont{STIX Two Math}

tikzcdset{arrow style=math font}

begin{document}

[
ato b qquad
begin{tikzcd}
a arrow[r] arrow[dr] & b arrow[d] \
& c
end{tikzcd}
]

end{document}