Filter based on Running diff value

[texasw]

I have a report in report studio where I have grouped by container number then added a data item to event type, then sorted by container number, event date and data item.
what I need to do is filter report where 2 is missing between 1 and 3, it is essentially a missing event. I can't work out how to do this? Please see attached data.

I also created a Running difference data item thinking I could find where OC is 5 and only show all data related to this based on BL or container number grouping...
see attached.
Also how do I filter group where there is only 1 row of data?