This is actually a pretty interesting technique. I appreciate you pointing me to it.
Your question is pretty vague, and without an example of what you have done, it is nearly impossible to tell you what you are missing or how to help you. If you can attach a packaged workbook (.twbx), we might be able to identify the gap.
In general terms, what he is doing is calculating the appropriate decade for the columns, and a "fake" value for rows, with a single value of "all." This acts as the row dimension/label, so when the user clicks all, it selects all the values in the row, just like it would for a dimension on rows. He uses a parameter for this value, but it would work equally well as a calculated field.