Question: Is it possible to create an 'outer swimlane' as a parent to existing swimlanes?

Context:

• A multi-dimensional swimlane exists within an activity diagram.
• Colleague feedback suggests condensing the number of vertical swimlane columns to aid in readability.
• Without re-creating the activity diagram from the beginning, the goal is to allocate existing stakeholder swimlanes into two outer (aka - parent) swimlanes: Internal Stakeholder + External Stakeholder.

• The option to create inner swimlanes is visible when right-clicking swimlane drop-down menus. Not apparent is whether creating outer swimlanes is possible in Cameo Systems Modeler 2021x.