I need to replicate, in a new database, the result of a view. Is there a
solution other than using an external process waiting for changes?

Below a broken example of what i need: a continuos filtered replica using a
reduced view as source:

curl -H "Content-Type: application/json" -X POST -d \
'{"source":"http://localhost:5984/datastream/_design/dbname/_view/viewname?group=true&group_level=3",
\
"target":"http://localhost:5984/dbreplica", "filter":"dbname/filtername", \
"query_params": {"key":"value"}, "continuous":true}'
http://localhost:5984/_replicate