The ability to add columns and measures to display folders in the new Modelling view is one of my favourite features of the November 2018 release of Power BI Desktop: it makes complex models a lot more user-friendly. Being an old-school SSAS developer, I immediately wondered if they worked in the same way that they do in SSAS – and the answer is yes and no.
The good news is that display folders can be nested. Say you have a table called MyTable with three columns called A, B and C. This is what it looks like in the Fields pane in Power BI Desktop by default:
If you select column A in the Fields pane and enter a name (in this case “My Folder”) in the Display folder property in the new modelling view, you’ll see column A is now displayed in a folder in the Fields pane:
That’s obvious. It is also possible to create nested display folders though, and you do this by entering multiple folder names in the Display folder property separated by a backslash \ character. For example, entering “My Folder\My Subfolder” in the Display folder property for column A like so:
…makes column A appear in a folder called My Subfolder which is itself in a folder called My Folder.
To give another example, if column B is given a Display folder property of “My Folder\My Other Subfolder” the result is this:
Note that while the screenshots above are from the new Modelling view, in the Fields pane in other places such as the Report view the folders are displayed in alphabetical order:
You may need to use numbers in your folder names to ensure that everything gets sorted the way you want:
[I’ve just noticed that in the screenshot above column C looks like it’s in the same folder as column B, which it isn’t – that needs fixing and I’ll report it as a bug]
UPDATE: it’s now possible to make a measure appear in more than one folder too: https://blog.crossjoin.co.uk/2020/03/16/making-one-power-bi-measure-appear-in-multiple-folders/