To do Alt + H + M + M on Mac in PowerPoint, download and install Accelerator Keys, then press Option, followed by H, M, then M.
Command: More SmartArt Graphics
This is how to do Alt + H + M + M on Mac in PowerPoint with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with PowerPoint.
Alt + H + M + M opens the full SmartArt Graphics dialog, giving you access to all available SmartArt categories including List, Process, Cycle, Hierarchy, Relationship, Matrix, Pyramid, and Picture layouts.