Well, since you are using week-related dimension values, there should be some underlying date value (like e.g. WeekStart()) Use that value to sort the X-axis from Latest to Earliest. The underlying date value includes a year, so you won't get into trouble with multiple years (like you mentioned in your other discussion on the same topic)
Then add ad dimension limit that limits the number of X-axis values to the first four. Or first seven in case of day values.