like so?
This is tricky and will involve some trigonometry. The top window is not that difficult, though, the position of the bottom depends on the angle of the upper.
Assumptions:
both angles are the same…
both windows are 'animated in the o’clock attribute, divided with a separator ;
you might wanna check the Animator extension…
here is the file, have fun!
windowfold.skp (261.1 KB)