1. A computer program product for use with a hierarchy encoded by containment, the computer program product comprising a computer readable storage device having program code embodied therewith, the program code executable by a processor to: in a first representation of a hierarchy encoded by containment and visually displayed as a first tree-map, display each object within the first representation as a shape comprising at least two opposing surfaces, wherein the first representation comprises one or more first objects assigned to a first tier in the hierarchy and one or more second objects assigned to a second tier in the hierarchy, and each second object having a second shape boundary nested within a first shape boundary of a first object; perform a selection from the group consisting of: select a first shape of a first object within the first representation, and designate the selected first shape to the second tier by moving the first shape towards a second boundary of a second shape of the one or more second objects in the second tier, wherein the selection and designation is a single action; and select the second shape of the second object within the first representation, and designate the selected second shape to the first tier by moving the second shape outside of the second shape boundary of any second object of the one or more second objects assigned to the second tier, wherein the selection and designation is a single action; and create a second representation of the hierarchy visually displayed as a second tree-map in response to the designation, including program code to dynamically re-order the objects of the first representation, wherein the dynamic re-order comprises a re-assignment of the first and second objects within the tiers of the hierarchy.