I implemented it by changing the plugin which opens the file path panel.
To do the file path auto completion on the panels, now it is necessary to import the class:
from AutoFileName.autofilename import FileNameComplete as NameComplete
def on_post_window_command(self, window, command, args):
if command == "hide_panel":
NameComplete.isOnFilePathPanel = False
isOnFilePathPanel = False
And set the attribute
NameComplete.isOnFilePathPanel = True, when opening the panel.