For outline level data to be used as an indicator of the tree structure, the levels must be in the range 1 >= outline level >= N
“N” is the maximum outline level. There are two perspectives on outline level:
- Excel limits: Excel only supports levels between 1 and 8. So the built-in controls etc only work up to 8 levels deep.
- Source data: the actual data you’re working with can have an infinite number of levels, it all depends on your data. Some Wikipedia category hierarchies are approximately 20 levels deep.
TreeWiz handles this with a compromise: if you have data with levels greater than 8, you have 2 choices:
- Group everything at level 8 and above at the same level of indentation in Excel
- Choose not to group rows with levels above 8
Typically, levels above 8 in most applications are very unwieldy to comprehend and manage, so this might not be such a big limitation. Wikipedia category hierarchies are very sparse which results in such deep hierarchies.
The outline level in your data can be a static value or the result of a formula, so you have many ways of creating outline structures, depending on your data.
Note that an outline level is context-free: the levels must be set correctly across your rows or columns for the outline grouping to work correctly.
Here is a simple example of data with an outline level, before and after grouping by TreeWiz: