Currently, there is a chance that creating a Focus Visual Style from a ListBox's Properties Panel does not offer the ability to store the Style Resource in a particular location. (see attached image).

Repro Steps:

1) Create a Project containing a MainPage.xaml
2) Introduce a ListBox to the Stage.
3) Select the ListBox, and in its Properties Panel, under the 'Styling' Header, open the expander to reveal 'Focus Visual Style'.
4) Click on the (+) icon on the Focus Visual Style's Row.
This will open the Resource Creation Popup.

5) Expand the dropdown adjacent to the 'Create in' label.
Observe how no storage options are listed.

Expected Results: The Focus Visual Style can be created as a Resource from the ListBox Properties Panel to a specific location between Element/Page/GlobalResources/ResourceDictionaries.