how to use parent field in child view in views field View
You will have to send a contextual filter from your parent view and catch it in your embedded view. There are plenty of tutorials on contextual filters, but this one should get you started:
http://www.metaltoad.com/blog/using-drupal-contextual-filters-views

UPDATE
you can set a contextual filter from your parentview by editing the embedded view in 'fields' and define it in the view-settings drop-down.