As an example, if an article journal has three or four authors, two of them is from the same country, it should be considered as international collaboration or will consider as both of local and international collaboration?
Yes, two (or however many) local and one international author is deemed to be an international collaboration.
However, another deciding factor as to whether an article will be deemed to be international research by a journal is whether the research was conducted only in the local country or in both countries!
I agree .. once there is an author whose affiliation is outside the borders of many others, there is a strong argument that it is an international collaboration.