The default Tasks list or Segment Maps list does not display assets inside subfolders as in the example shown below.
To view assets inside subfolders, first click on the Browse folders and filter items icon. Next, click on the ⋮ and select Configure views.
Select whether you want to view assets for the selected folder only, or for the selected folder and subfolders.
Click OK and your view will now show assets inside subfolders as in the example below.