This is a plugin that gathers your match data from Ancestry in the context of your browsers. While there is a rudimentary (disabled) UI, it's no where near as good a visualization as the Cluster function from MyHeritage or Genetic Affairs.
To use this, load it as an unpacked extension, then navigate to the DNA match list URL. Click the extension icon and set your CM ranges, then select "Set Match List." When it completes it will tell you, then choose to gather shared matches, and when it's done, download the CSVs.
Enjoy.