Publisher can be configured to pick up publish transactions filtered by Priority, Publication, Publication Target and Hostname.
As of SDL Web 8.1 publishing is configured to target type/purpose in the new style publishing via Topology Manager. It is possible to find TCM URI of the emulated publication target (by running a database query) and filter by it, but it is not shown anywhere in the UI.
Provide possibility to configure Publisher to pick up only publish transactions with specified purpose (to have, for example, a dedicated publisher for Live/Prod destination).