Hi GrantThrall-4410,
1.Make sure your virtual machines are sending CPU usage data to Azure Monitor. If you don't see the data, check if the "Percentage CPU" metric is available for your resource type. Sometimes, certain metrics may not be available depending on the resource type or Azure region.
2.Verify that your account has the appropriate permissions to access and view CPU usage metrics for the virtual machines in Azure Monitor.
3.You can try clearing your browser cache to see if the option appears. Occasionally, UI elements may fail to load properly due to browser issues.
4.A simple refresh of the page can often resolve problems with selecting metrics.
Could you please kindly take a moment to review the provided links similar type of exercise and watch the video, then attempt to complete the exercise?
https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-overview
https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-visualizations
If you encounter any difficulties, please feel free to reach out for further assistance, and we'll be more than happy to help.
If the solution provided has helped resolve the problem, please consider giving it a "thumbs up".
Thank you.