For Transition Boundary Condition, the
Surface Current Density subnode as an one-sided surface current density is available from the context menu (right-click the Transition Boundary Condition parent node) or from the
Physics toolbar,
Attributes menu.
For the Surface Current Density subnode, select
Side —
Upside (the default) or
Downside to define on which side the
Surface Current Density is applied. The red arrow visualized on the selected boundaries always indicates the upside.