My scenario is 

i have 2 many2one field .by default the selections coming is all the available data.

i want as

when i change a value on first many2one field the other many2one field will show the related informations only except all the data.

All the fields are interconnected through models.and also i am getting how many record to display but unable to show as a dropdown of all the related data.Please Help me

Thanks and regards.

Gouranga Kala