@staabm @havvg I don't have the complete example to show you what I am doing right now.

It will be helpful for me if I would have got the errors as an key value paired array. If not I will build it myself :) .
@staabm about you question what Aura does .

I can say what I am doing ,

I am creating a form, validating and filtering the user input, and using propel to save data. In the behaviour I have added to unique for email, so there propel gives me validation failure.

It would have been helpful if I can populate the errors back to Aura.Filter, so the assigned value can be displayed at the same place. I am sorry if I cannot convince what I am doing.