When I had this it worked fine:

// Define menu stacks like this
static const menu_stack_t logoMenu = {
	.menuDepth = 1,
	.rows = {{ .menuFunction = &display_logo }},
};

// declare and array to hold them
menu_stack_t columns[10];

columns[0] = logoMenu;
columns[1] = gainsMenu;
columns[2] = metersMenu;
...

//and access like this:
if(columns[mainMenu.columnId].rows[mainMenu.rowId].preDisplayFunction != NULL ){
	columns[mainMenu.columnId].rows[mainMenu.rowId].preDisplayFunction();
}

But, I think this means I am using space twice, and columns will be getting a copy of the struct, and I need to save memory

so I want to make columns into an array of pointers to structs:

static const menu_stack_t *columns[]{
    &logoMenu,
    &gainsMenu,
    &metersMenu,
    ...
};

and then access I think I access it:

if(columns[mainMenu.columnId]->rows[mainMenu.rowId].preDisplayFunction != NULL ){
	columns[mainMenu.columnId]->rows[mainMenu.rowId].preDisplayFunction();
}

But when I fire up the debugger on the embedded target, the array appears to be full of junk