If you right click on the part in the tree, there is an option that I believe is called "Component Constraints" somewhere in the menu. I'm trying to verify this, but Catia won't start up for me right now. Once you find that, click on it and it will highlight the constraints (both in the tree and on the model) that are connected to the component. I usually hide all constraints, then use the "Component Constraints" tool and once all the component constraints are highlighted I right click and show (which shows only the component constraints).
If I can coax Catia to actually start and I can verify this, I'll edit the post with the correct information.
Edit: Right click on the part/sub-assembly in the tree > Select the option that is "Instance_Name.X object" > Component Constraints
