Note: I'm going to move this post to the filebeat forum, because I think your question is really about that product than Elasticsearch.
If you are using the HAProxy module then you almost certainly already have separate fields per this doc:
I suspect that the issue is simply to do with way you have been looking at your data so far.
Firstly, you should have a sample dashboard already as part of the beat setup.
If that's there and is showing graphs of response codes (etc) then that's a pretty good sign that everything is working correctly.
If you want to get face-to-face with your data, then try the Kibana Console. Jump over there and then perform a _search (docs) on the index you're using for your HAProxy data. It should show you 10 documents (the default limit), and all their fields.