Methods, systems and computer program products for displaying a set of hierarchical data in a tree diagram are provided. One or more of the elements in the set of hierarchical data may include a set of embedded hierarchical data. The tree diagram includes at least two different parts, where the first part has a plurality of vertically oriented levels, and the second part has a plurality of horizontally oriented levels. The set of hierarchical data may be displayed in the first part of the tree diagram, and the set of embedded hierarchical data may be displayed in the second part of the tree diagram. One or more elements in the set of embedded hierarchical data may also include embedded hierarchical data. This doubly-embedded hierarchical data may be displayed in the first part of the tree diagram.