To start, click Portfolio on the left panel of your screen.
Then, as shown below, click on the three circles in the top right of the screen, then select Company metrics.
Then, as shown below, click on New company metric in the top right of your screen.
Finally, you may customize the metric's name, description, category, frequency, unit & format, aggregated value, and select companies you want to track with this metric.
Once finished, select the blue button Create at the bottom.