\input{umtest-preamble}
\usepackage[bold-style=ISO]{unicode-math}
\setmathfont{Cambria Math}
\begin{document}
\[\GREEKmathbfup\]
\[\GREEKmathbfit\]
\[\greekmathbfup\]
\[\greekmathbfit\]
\end{document}