A Sub-flow is, unlike regular Flows with either User Intent Triggers or Prompt Triggers, not triggered by user inputs nor script expressions; Sub-flows are activated using Flow Links in a regular Flow which then refers to the Sub-flow.
When a Flow Link points to a Sub-flow, the currently active Flow will stay active after the Sub-flow is executed; that is to say the regular Flow is executed first up to the Flow Link, then the Sub-flow runs and, when completed, the control returns to the regular Flow to continue execution.
Change Flow to Sub-flow
This section currently only apply to Teneo Studio Desktop
To change a regular Flow to a Sub-flow, with the Flow open, simply click the Sub-flow button in the top ribbon of the Flow; this will convert the Trigger node into a Sub-flow node.