Hi Igal,
If I've understood your question correctly then I use Timelion to achieve what you're looking for. I'm not sure if its possible with any of the other Kibana visualizations, but there are lots of people on here who know more than me so I'm sure you'll get an answer....!!
Below is an example of my Timelion visualization which is creating a series for each of the possible values within a particular ES field:
The dynamic labelling uses the fact that Timelion allows Regex (including capture groups) to auto-generate labels from your data. I'll be totally honest here - I grabbed this from another forum post - see https://discuss.elastic.co/t/timelion-how-generate-label-dynamically/85072
I suspect the above link should tell you what you need to know to get this working in Timelion.
Hope that helps,
Steve