this seems like it should be simple but having a hard time finding the answer...
I have a line chart with time dimension on X - Axis and Amount of Sales on Y-Axis. The product dimension is what is plotted on the line chart. All I want is to have the name of the Product plotted on top of the line in the graph. for instance we have product Shoes being plotted in the graph how can I get the name "Shoes" on the graph (not just in the legend).
Oh, I thought you had only one dimension, Product. Sisnce oyu have Year/Month, line chart makes sense. In any case, I don't understand why you get this error. You should've got correct chart but with Product label on each data point. Not what you need anyway. The sollution you're looking for is closer to what Gysbert suggests - leave your major expression as is, without dual, and add another expression with dual only for the labels at the beginning of each line.
I am getting close - if I select only one product it will put the label name on the line. However I want all products to show but if I don't select a specfic product it just adds them all together with one line (and no label of course)