These?
As I understand it, it’s not a “path” it’s a tree. So transitional forms refer to ancestors on the tree that are genetically related to one another. I posted tree of human ancestors and an article with an explanation that many of these species coexisted for times. There is no linear progression.
What do you mean by “the terms of this thread.” Transitional fossil means a fossil that has traits common to an ancestor species and a later species.