1. A computer-program product tangibly embodied in a non-transitory machine-readable storage medium, including instructions configured to cause a data processing apparatus to: receive data associated with nodes of two or more hierarchies, wherein nodes are associated with original node values; identify a common level node and a target level node for each of the hierarchies; identify a linking constraint, wherein the linking constraint includes a rule to adjust a node from a hierarchy to make it consistent with a node from another hierarchy; apply the linking constraint to the common level node of each of the hierarchies, wherein applying the linking constraint includes generating updated common node values associated with the common level nodes, and wherein updated common node values are the same node values; apply the updated common node values to the target level node of each of the hierarchies, wherein applying the updated common node values includes generating updated target node values; and generate a resolved hierarchy using the updated target node values.