Hi,
It depends on your needs. You can start by using NGSI-source to receive the entities or changes, and visualiza them on an ol3-map, or use directly the entities. After, usually you want to choose a specific attribute of your data, for example with value-list-filter you indicate in javascript-like syntax which path to attribute to extract from any.
After, you can use any generator to build the graph for you. There are several at https://github.com/Wirecloud/agile-da.... There are plenty of ways to connect, I leave here a screen capture of a created dashboard wiring where you can see some examples.
https://drive.google.com/open?id=1cRi...
Best regards,
Miguel