Column Folders
Unlike measures, columns are not automatically organized into folders. Instead, columns are organized underneath the table name, in a tree-structure. Report-builders can expand each table and navigate the columns within. Like measures, however, you can create custom folders and arrange columns into those folders. Only visible columns can be organized into folders, and this can be done from both the Tables panel and the Columns panel.
Custom Measure Folders
A column folder can be specified from the column's properties (green highlight below).
You can create a new folder simply by writing the folder name in the Folder field; you can add as many columns as necessary to that folder by writing the same folder name for multiple columns from the same table.
Each folder is bound by the table, so that only columns from the selected table may be added to it.
When the table is expanded by the end-user, the folder will appear; the user can expand the folder to navigate its contents: