Combining 3 Measures into a Single Measure

norken20 

You can try following this method.

1) create a new table (I've called it "Select Measure") using the "Enter Data" option in the ribbon under the Home tab. Type in the names of your measures (and optionally an index column for ranking purposes). In my example, I'm creating a table to be able to select bewteen the measures "Sales 2018", "Target 2018", "Sales 2019", and "Target 2019".

 2) Create new measures for each of your meaures to be used in your line chart visual following this structure for each:

Sales 2018 (Single Sel) = IF(SELECTEDVALUE('Select Measure'[Selected Measure]) = "Sales 2018"; 
                            [Sales 2018]; 
                            BLANK())

 3) Add these new measures to the Values bucket in your line visual:

4) create a slicer using the new table you have created (with the measure names) and in the formatting pane for the slicer turn on th "single select" option:

And you get this end result:

If you need to show more than one measure at a time in the line graph, we need to tweak the measures. Let us know if you wish to do so.