With the Monitoring/BI Reports
You can see the channel name in the Title column of the BI Reports > Applications & Websites report (or the App / Webpage column on the Monitoring > Web Pages & Applications report). You can also use the TITLE filter with the channel name (e.g., "general") to filter the report:
Similarly, you can look for the text, "huddle" to detect any huddles.
With the Behavior Rules
You can also use an Applications and/or Websites rule like the one below to detect slack channel discussions and huddles as they happen:
