Creating symbols at specific data points in a line chart
I have a line chart that has 2 dimensions and 1 expression. One of the lines has two spikes, where I want to add a symbol to describe what they represent. If I add an additional expression, the graph changes completely. If I add an additional expression, the graph changes, so that won't work. Is there any other way to do it? This should be a simple operation but I'm not finding a solution for that.