Have you tried using a reference selector with source as microflow?
When you add a reference selector to a dataview, go to properties (set the attribute) then go to the third tab (selectable objects) > Choose source to be microflow.
Now in this microflow you can return the list that you want, and that will populate the drop down.
Hi Rob,
A really great, but not well marketed feature is the contrained by option on reference selectors.
Constrained by gives you options that are more limiting than pure XPath but are updated in realtime. And this might be exactly what you need.
Lets assume that you have a page: Employee_Edit where users first enter the region and then the office.
If you constrain the office to follow a path to the current exmployees region than the options in this reference selector will automatically update based on the selected region. See my screenshot
Hope this helps,
Andrej