Get price where vertical line of crosshair and line is interseting

Question

I have a chart with lines and I want to get the price of every line, in the point where the vertical line of crosshair is intersecting them.

Red circles are the prices for which I am looking for.

This is the crosshair movement:

chart.subscribeCrosshairMove(param => {

  console.log(param.seriesData.get(buyLineSeries));

});

For now I use param.seriesData.get(...), but this is returning the value only if in the intersection point, is also a point in lineSeries data.

How I can get the prices from any position of the line?