Quoting MARIMUTHU Ilayaraja:
> Tosh,
>
> It means the user can edit that particular field for all the bugs?
> Howz this access control works. For example, I have user A who can
> access only the product A++. But I have another product/group called
> B++. So the user who is under ReleaseManager group can edit the
> bugs(custom field) in all the products?


No, this should only add to the existing restrictions. If user A
attempts to edit the field in product B++, he/she will not be able to
edit that product at all, and the change to that field should fail. I
believe. You will need to test it out to confirm.