Overlapping data series with Live Connection

I'm accessing my data from a MSAS cube with Live Connection.  I have 3 data series: history (actuals), a near term forecast, and a long range forecast.  I want to use a line graph to show the continuity (ie. that neither the near term or long range forecasts have unexplainable "jolts").  Because I need to retain a history of the near-term forecasts I can't delete these.  Because months are "in progress" I get a tailing off of the actuals.

What I want to be able to do is filter the actuals for completed months, have the near-term forecast for just the current month and the following 2 months, and the long-range forecast for the 3rd future month onwards.  I would then plot these on an axis of months.  As the data has many dimensions (customer segment, state, product type) I want to have this all on one graph so that the vertical axis will resize as required.  3 graphs side-by-side is not my preferred outcome.

Here's what I currently get...

Green line should stop at March 2019.  Black line April 2019 + May & June.  Red line from July 2019 onwards.

Thanks in advance.