Select only region of window

i want to use element exist activity so i can verify whether that sub window is coming or not.But,with this element exist activity,it select whole window.i want only sub window to be selected.

@Ananya1 Explanations using Screenshots will be helpful :sweat_smile:

@Ananya1 selector will be different right, try to use active activity and pass the selector to it. so then it will select your sub window on top and then do the activities