Stacking Dimensions in Columns and Rows Boxes
To stack or nest Dimensions:
1. We can start with a Slice like the one shown in the following image, with selected months (Jan, Feb, Mar, Q1) in Columns, and selected cost accounts in Rows.
2. Select a Dimension from one of the boxes (Filter, Column, Row)—here, Year—and drag it below Month in the Columns box; then drag Account so that it now appears below Year, as shown in the following image. This is what is called “stacking” Dimensions
3. Next, double-click on Year, and in the Select a Member dialog for that Dimension, select 2019, 2020, and 2021 to display those Members. Click Insert, creating the Slice in a New Sheet (assuming New Sheet is selected).