Chart.CategoryLabelLevel (Word)

Returns or sets an XlCategoryLabel constant that specifies the source level of the chart category labels. Possible return values are xlCategoryLabelLevelAll - Use all category label levels within range on the chart. The default, xlCategoryLabelLevelCustom - Indicates literal data in the category labels, xlCategoryLabelLevelNone - Use no category labels in the chart. Defaults to automatic indexed labels.

ActiveDocument.Background.Chart.CategoryLabelLevel = xlCategoryLabelLevelAll