Drilling Down and Up in a Hierarchy

One of the most useful ways to navigate hierarchies is to drill down or drill up. For example, if you are examining the sales totals for various years, you can then drill down and view sales for all of the months within each year. Alternatively, if you are examining sales totals for all months, you can then drill up and view the sales for each year.
You can drill down and drill up in Tableau by clicking on fields placed on shelves, or by selecting a hierarchy header in the table. These two methods are described below.

Using Fields on Shelves

You can drill down or drill up by clicking on a dimension that is placed on any shelf. If the dimension is on the Rows or Columns shelf, drilling down shows more data (more headers) in the table, while drilling up shows less data in the table.
You can click on the plus/minus control that appears on any hierarchical dimension on any shelf. If a dimension member shows the plus sign , then its children are not already showing and you can drill down at least one level. If a dimension member shows the minus sign , then its children are already showing and you can drill up.
The following figure demonstrates drilling down one level in the hierarchy for the Region dimension to expose the states within each region.

Using Headers

To drill down and drill up for individual dimension members in a hierarchy, right-click a table header and select Drill Down or Drill Up from the context menu. This is often referred to as non-uniform drill down because you expose only the members of interest instead of exposing all the members of a given level.
For example, the following figure illustrates drilling down into the Root Beer member of the Gen2,Product dimension. Note that new row headers are displayed in the table and that Gen3,Product, which is the next generation in the hierarchy, is automatically displayed.

One reason to use non-uniform drill down is if your data source has a ragged hierarchy (asymmetric layout). You also might want to view the children for just the member of interest.

Drilling down and drilling up results in filtering the data.