How to Measure displacements (U1,U2,U3) of a node From a specific point ? (reference)

[Damith14]

Im trying to measure/plot the displacement of a bending actuator, and i want to measure/plot the displacement of the node from a certain point on the actuator. How can i do it ? any help plz

 

[Mustaine3]

With a connector of type CARTESIAN.