If you have multiple constraints on the same object, these buttons move the constraint up or down on the list. Constraints in Unreal Engine are hierarchical and override other constraints higher on the list (only if the constraints animate the same channels). New constraints always take priority over older ones and are placed lower on the list. Because constraints can be overridden, it is not always necessary to deactivate other constraints. For example, since Parent Constraints animate all transform channels of a control, simply activating one is enough to essentially deactivate all others, so long as the one activated is higher priority. In this example, although both constraints are active, only the root constraint is providing the constraint effect due to it being lower in the list and higher priority