The Segment is the lowest level of granularity in Flex Insights conversation data, representing the individual segment within the conversation.
The Segment ID is a Primary Key for the Conversation data set.
The Taskrouter Task SID is contained in the label "External ID" on the "segment" attribute.
When you add the segment attribute in a report, you can choose which label to display:
A short video demonstration on how to display the task SID from the "conversations" tab in Flex:
A demonstration on how to display the Task SID from a KPI dashboard: