I'd take a look through here. There are two methods highlighted in this thread. The one produced by Tom works well and works using a slightly hacked query. The one produced by me further down in the thread is a variant of this and can be produced without such a hack.
This worked like a charm and saved me alot of work and headaches! Thank you!
This could be achieved by selecting the below criteria.
When creating a query with criteria, the conditions Is Within My Groups is
now available in the LANDesk Serive Desk 7.7.3. This is the one which everyone is looking and got added in the LDSD 7.7.3.
incident.current assignment.group = Is Within My Groups