Hello,
Assuming that you process a full discovery, collection and upload every time, the above would be one way. Another would be to view your inventory in Comprehensive view, the go to Library>Inventory>Custom Inventory and add the field "Collection Date". This can be done by right-clicking in any of the column heading search fields. Select the "Collection Date" field and it will be added to your screen view. You will then be able to see and filter by the last time each was collected.