Lambda Error count and success rate -- where to drill in to error details?

Maybe a dumb question but I couldn’t find a good answer …
The AWS Lambda dashboard has a handy chart like this, showing me that I have a few errors in some of my functions:


Question: How do I drill in to find out which functions are contributing to this error count? I can’t seem to find an easy way to identify where the errors are coming from. Searching each Cloudwatch log group (I have dozens) doesn’t seem very efficient … and also I’m not sure what I’m searching for.

There must be a better way. Any advice?