Constraint links
You link items on the Constraints Diagram with constraint links. Two linked constraint types have a parent-child relationship, indicated with an arrow pointing from parent to child.
An association between a constraint type and a constraint is shown by a line. A constraint type may have many constraints linked, but a constraint can only be owned by one constraint type. You cannot link two constraints to each other.
To link items on a Constraints Diagram:
1. Select the icon on the Constraints Diagram tab.
2. Left-click inside the source item of the link.
3. Left-click inside the destination item of the link.
Your two items should now be linked.