The description of the properties that represent the dimension determines the labels in VBD planner. If you want to change the default text (label), change the description of the corresponding property under the Data-Decision-IH-Dimension-<DimensionName> class.
You can also customize how dimensions are displayed in VBD planner. The pySetupDimension activity under the Data-Decision-VBD-DimensionDefinition class can be circumstanced by dimension name. You can override the pyLevels value list to define a different sequence of properties for a given dimension, for example:
You can set the default level to be displayed for a dimension by overriding the pyDefaultLevel property for a given dimension, for example: