How to watch the watchers?

Is there a simple way to create a kind of dashboard or simple an index to track the execution history of the watchers as well as the watcher setup?

Yes; first be aware of the ILM and Template for the watchers, by default they are deleted automatically after 7 days. For the watcher execution, create a Kibana Index with the index pattern ".watch" (Enable "Include system and hidden indices"):

Then you could work your way to a very complete dashboard, as an advice, include metadata categories in your watchers to better organize and filter:

@Iker Thank you! That's is exactly, what I need!