Project & Issue Visibility

Hello.

In our company we have 2 departments that use Youtrack, the Web department and the Software department.

The projects are, mostly, separate but there are cases that some issues, in specific projects overlap.  For example, if the software dept must create a view in the SQL Server for the project AAA, the web dept creates an issue and assigns a software developer.  The software developer should see only the issues he created and the issues he is assigned to, in the project AAA.

To achieve this, I created a role (Collaborator) that does not have read issue permission and 2 groups (Web Collaborators & Soft Collaborators) that include the respective users from each dept.  Then I added the Soft Collaborators group to the project's AAA team.  The problem is that, while I can assign a software developer to an issue, he cannot see the issue.  Even when I explicitly add him to the visibility of the issue, he still cannot see it in the list.  The only way to see it, is if I add the read issue permission to the role Collaborator, but then he can see all the issues of the project.

What I am trying to achieve is that each issue is visible to the each project's team and then only to the creator and assignee. How can I resolve this visibility issue?

Thanks