Question about Multi-Select Filter

[Anonymous]

Hi Power BI developers,

I am creating a line chart, the aim is to visualize the average score for fleets. 

I want to have the ability to multi select 2 or more fleets and see the comparision between them. i.e. when I select 2 fleets, I want the chart to have 2 lines showing up so I can see the comparison between the 2 fleets.

My question here is not that I don't know how to multi select, I know I can use ctrl+click to select multiple values from the filter, my question here is that, when I multi-select 2 fleets, there is still only one line showing up on the line chart, and I think the reason should be because in the Y-axis value of the graph, I only put one value into it which is the DAX to calculate the overall average score.

I think one potential solution is that I create DAX measures to calculate the average score for each fleet, and I put all these measures into the Y-axis of the line chart. But the problem is, I have around 70 fleets, is this really a good idea? Will this take too much storage and affect the performance of my power bi report? Do you have any better suggestions to solve this question? Thank you so much!

Below is the line chart and fleet slicer I am talking about:

Below is the Y-axis value that I currently put in this line chart:

[lbendlin · Accepted solution]

Put the Fleet field into the Legend area of the visual