The Shape drop zone is enabled when working with charts that display data points: line, point, lollipop, area, stream, scatter, and bubble charts. It is used to drive the shape of the data point, witch each element in the hierarchy represented with a different shape.
The Shapify function in the Value drop zone context menu allows you to use measures to drive the shape of the data points.
How to Shapify Measures
Start by adding a single measure to the chart.
Add your second measure to the secondary axis, making sure to drop it in the "All" Column, for the chart type that you are using. For instance, in this example, a line chart is used. So, the second measure must be added to the Line Chart, All zone (green highlight):
This will result in your measures being added to the same chart and automatically colorized.
To shapify your measures, open the Values context menu and click Shapify,
Your measures will be copied to the Shape zone, and a combined color shape legend will be produced automatically. The shape of the data points in the chart is now driven by the measures in the Shape zone.
You can continue adding measures to the chart in the way described in Step 2. Each time you add more measures, you must repeat Step 3 to apply the Shapify function to newly added measures.