The Design Panel is where you configure the crosstab. It consists of five tabs, but the primary tab you will use is the Analysis tab.
The Data Source area displays all fields of the data source available to analyze. If there are many fields, you can use the Find option to search for a specific field. The Rows/Columns areas display all fields that are currently in the rows or columns of the crosstab, and the Background Filter area displays member filters of dimensions that are not displayed in the crosstab but still restrict the data being read from the data source.
You can show or hide the Design Panel as well as choose to display technical names or not.
To analyze data in the crosstab, you drag fields from the Data Source area into the Rows/Columns area.