How to selectively forward the log files to specific indexes in Splunk?

Is it possible to selectively forward the log files to specific indexes in Splunk. I want to forward a docker container running 3 services logs to Splunk indexer, the problem is that if I use Docker logging driver, all the data written to STDOUT goes to the same index and data segregation is not possible. Instead of that I've setup forwarder and able to send logs but all are going to the same index, I want to configure splunk forwarder to send specific logs to a specific index.