how to make cluster

Hi, Emmad.

Hi, and welcome!

Please see the FAQ: What's a reproducible example (`reprex`) and how do I do one? Using a reprex, complete with representative data will attract quicker and more answers.

Without a reprex it's not possible to tell, because the locations may be x,y coordinates in a single object, two separate objects or part of an sf or sp object. It's also unclear how the two points are to be represented as being related somehow. Is this, for example, a convex hull on a plot? Does it matter if other points are also included.

Do you see my questions clearly?