The extraction functionality allows for extracting a selected part of the state machine diagram to a newly created diagram. After extraction, a submachine state is created in the source diagram in place of the extracted part(s). The submachine state is a referencing element that references the newly created state machine diagram.
As you can see in the example, during the extraction, the selected part of the state machine diagram is moved to the newly created Login state machine diagram. In the source diagram, a Login submachine state is created in place of extracted elements.