Nested connector end (SysML item)
The NestedConnectorEnd stereotype extends a Connector's start and end Roles so that the connected property may be identified by a multi-level path of accessible properties from the Block that owns the Connector.
When you create a Connector on an Internal Block Diagram that is nested more than one level deep, Modeler applies the «NestedConnectorEnd» stereotype to the Connector's start Role and end Role. The tagged value of the propertyPath tag definition records the path from the Block that owns the Connector to the item that is connected.
From the Property Pages for a Connector you can open the Property Pages of its Nested Connector Ends - on the Connector's property pages, click the Start Role or End Role tab, and then click the 
Properties button.
Properties button.