A while after asking this question, I found the answer by chance (because I had stopped researching), I saw a boy talking about some essential resources, among the resources was there! MARKPLACES <3 ...
It was love at first click, and I discovered a very complete documentation of Google!
Some Applications are required to display a large number of Locations or markers. Naively plotting thousands of markers on a map can quickly lead to a degraded user Experience. Too Many markers on the map cause Both visual Overload and sluggish Interaction with the map. To overcome this Poor performance, the information displayed on the map needs to be simplified.
Everything I wanted to know about the grouping of Marks is there, very good and recommend!
Making a plug-in for Wordpress with this documentation became easier!
It is possible to make a similar effect by following the steps mentioned in this link.
– Emanoel
@Emanoel if you want to give an answer explaining this link and bringing example of how to implement the plugin would be an interesting response.
– Sergio