A target curve in Spotfire


In Spotfire, I am trying to draw three horizontal curves from columns in a different data table than my plot. These lines are supposed to be target lines. I know I can do this either in a combination chart or in Lines & Curves in properties.

However, I prefer not to do it in a combination chart as I have to add colouring and I get many distinct series when I add colouring to three different target lines.

So I tried doing this by adding a horizontal line in "Add > Horizontal Line > Line From Data Table". However instead of drawing a curve what this does is draw multiple horizontal lines for the slightly fluctuating values in this column. I have also tried other options in Lines & Curves but none seem to work. And this happens although I have matchedthe data tables.

I have also tried adding in columns from the other data table, but without much success.

Does anyone have an idea how I can draw these target lines while avoiding the situation linked below?

The situation now:

(1) Answer