In our organisation we are using Scrum process. In our version of Scrum, bugs created in backlog, along with a user stories e.t.c. Developers choose to pull bugs in sprint. When developer finishes to fix a bug, he will pass a module with bug fix to QA. When developer fixing a bug, QA engineers may find more bugs, that look different, but have a same root with a fixed one.
So, we have a situation: a number of bugs in sprint, and number of related bugs - are not.
I have an ugly solution: custom field "Need review". By default it's "No". But when QA finds, that fixed bugs are not only pulled to sprint, but also in backlog, he will set "Need review" field to "Yes" for bugs in backlog.
Developer have a quick filter in Scrum board called "Need review". He have a duty to check the bugs under the filter, and if it is some - review them, pull in sprint, set "Links" field and mark as Done.
I hope you can understand my messy explanations. Any recommendations how to do it a smart way using GreenHopper are very appreciated.