Managing the List of Constraints
The list of constraints in the Kinematics tab shows the constraints applied to the selected object or objects in the Shaper viewports. To view all of the constraints for a model, select all Shaper objects.
Constraints are taken into account in the order that they are listed. The position and the orientation of an object are evaluated separately and assigned to the first constraint in the list that applies to them. Constraints further down the list will have no effect on an object's orientation or an object's position if it has already been constrained.
Constraints cannot create circular reasoning. When a new constraint would create circular reasoning, an error will appear indicating the object of the constraint causing the conflict. If you really want to create the new constraint, you must first delete the conflicting constraint from the list.
To modify an existing constraint, select it in the list. Use the 
button to activate an eyedropper, then select a new target in the viewport. The new target will replace the old target in the selected constraint.
Use the 
button to delete the selected constraint from the list.