Axis labels are placed based on the start and end range values and we can add any number of labels to an axis.
In this example, you can see how to group axis labels. You can customize text in each level by using alignment, overflow, textSytle and border properties. Axis labels in each level can be arranged smartly using overflow property. Trim - Trim the label when it intersect. Wrap - Wrap the label when it intersect. None - Shows all the labels. Border of the axis labels can be customized by using type property. Rectangle Brace WithoutTopBorder WithoutTopandBottomBorder CurlyBrace withoutBorder. More information on the multi level labels can be found in this documentation section.