To do Alt + H 5 on Mac in Excel, download and install Accelerator Keys, then press Option, followed by H, 5.
Command: Decrease Indent
This is how to do Alt + H 5 on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + H 5 decrease Indent moves the cell contents to the left within the cell. This reduces the indentation level and is useful for organizing hierarchical data.