Depending on your selection in the Navigation pane, it is possible to archive by client or by individual VM or volume. If you select a Hyper-V server or an ESX server in the Navigation pane, you can select individual VMs to archive. Similarly, if you select an NDMP device in the Navigation pane, you can select individual volumes to archive. If you choose to archive by individual VM or volume, you can only archive backups for one client at a time.
If you select any other type of client or the Unitrends appliance in the Navigation pane, you will be able to select what to archive at the client level only.
Note on archiving NDMP clients: If you select an NDMP client when archiving by client, backups that fall in the specified date range and backup types will be archived for all volumes on the device.