Google is currently testing a new live messaging feature to chat with My Business customers directly via the local knowledge graph panel.
The pilot of the feature is started with some businesses are invited through emails to participate in the pilot program, and allow searchers to message busniesses directly from Google Search resutls.
According to Google when a business opt for the feature, a new message button will be added to their local listing on Google search pages. Using this message button, users will be able to initiate a chat with the businesses.
Below you can see the screenshot of the message button shown in the local panel on Google:
Google has published a help document for the feature HERE.