How to Identify if a given activity was processed by Routing

Summary:

We have a scenario where we have scheduled a Bulk Routing and then followed by Sequential Routing, say when the Bulk routing started the run there were 10 activities and during this time there were other new activities (say 10) that arrived in this bucket, the issue we are faced with is the Sequential routing seems to consider all the 20 activities and not restrict to the 10 that was processed by the bulk routing. The ask is do we have a mechanism to identify the activities which were picked up by Bulk routing so we can place a filter