There’s a nice new feature in Power Query Online (the version of Power Query used in Dataflows): parameters of type List. You can see this as a new option in the Type dropdown in the “Manage parameters” dialog:
Why is this interesting? In the past, Power Query parameters were always single values like a date or a string; now a parameter can contain mutliple values.
There’s one other new feature in Power Query Online that goes along with this: In and Not In filters, which can use these new List parameters.
I’m sure there are other cool things you can do with this but I’ll leave them to future blog posts.