Scenario (in v220.127.116.1182):
Create Sub-Group of Joinless group (which is 2 levels down from Root) and set the permissions of new group to Private (Listed). Add forum applications and an Ideation. Add a Browse Ideations and Browse Forums widget to the Sub-Group home page.
As group creator/owner (and site admin), can see everything as expected.
Edit site role permissions for the following: Everyone = Remove all permissions (one must be logged in to know of this group's existence); Registered User = Remove all permissions except Read Group, View Group Name in Lists, and substitute Join Group instead of Join Group by Request (as the goal is to suppress content from the group unless the user opts in to the group on their own).
As group creator/owner (and site admin), the Browse Ideations widget now reports no results could be found (despite the Ideation quite clearly existing), Browse Forums still shows correct forum applications.
As a generic Registered User, all widgets report no results could be found (as expected) with button to click to join group (as expected).
Return to edit Group Permissions, Select Owners from Group Roles, make no changes and click Save.
As group creator/owner (and site admin), can once again see everything as expected.
As a generic Registered User, the Browse Ideation widget now shows the name of the ideation created (should not be visible, and clicking on it returns the "Page Not Found" error as if you navigated to a page which you aren't supposed to know about (that at least is expected)) while the Browse Forums widget reports no results could be found (as expected) with button to click to join group (as expected).
It seems that whichever permission was last applied to seemingly any role, is the permission that is applied to all roles.