Remove From Segment Step
The Remove from segment step unsubscribes the current lead of the run from the selected segment. It is available only to For dialogs automations because a background workflow does not automatically receive a current lead.
Configure The Action
Choose the step from the catalog. Then select it on the workflow, choose a segment, and save the settings.

The action does not delete the lead, dialogs, or lead data. It only changes membership in the selected segment.
What Is Validated Before Execution
A segment is required. Publication is blocked if it is missing, archived, or belongs to another project.