Depends on context. It is usual for methods in general in any language to just look at the fields they need on the object when it needs those fields, unless there's some reason not to. For instance, you might have a case where you want to call the same method on different fields on the object; in this case, you'd pass them in an argument. Having two separate functions for the sake of having the same behaviour with different fields falls under "copy paste" code and therefore "silly", in my book.
I also would advocate against keeping non-owning references to other objects in your class just for the sake of a single method. In general, pass in external dependencies as function arguments, unless it is necessary or significantly more convenient not to. The dependencies of any particular method should be evident to the caller. A class should store exactly the fields it needs to fulfill its design contract and no more than that.