Source names specified in maintenance windows have to be an exact match - alternatively, you could use source tags to cover arbitrary groups of sources. Hope this helps!
Thank you for the clarification. I see that tag paths are supported for alert tags. Are tag paths supported in source tags and what would be the way to way to cover arbitrary groups? For example, if I wanted to cover only us-west production MongoDB nodes, would a west.prod.mongo tag work? Also, if I wanted to cover all us-west MongoDB nodes, would a west.*.mongo tag work? Also, if tag paths do work for source tags, can I use multiple *s? For example, west.*.mongo* (for both west.prod.mongo-master and west.staging.mongo-slave)