I’ve wanted to create this similar type of view with the year lines stacked with Jan - December on the x-axis.
It would be great if the line chart could support this type of view out of the box rather than just display the month value but still consider the year chronologically in the x-axis.
The workaround is to use custom fields to extract the Month and Year values and set the custom fields to type string, rather than datetimes which is what the chart is doing in your view.