Revisions API

I can use the API to get a list of revision

In the results I can see the grouped revisions (only the first of group contains ‘created_by’ so I have a list of grouped revisions (for eaxmple: 0,1,2 and 3 are one change. In TapeApp I see them grouped as well, but I can not find a way to set the from/to in the API.

The view in TapeApp is better because if you fill a multi_relation field in the API it will show like this:

from: empty to one
from: one to one,two
from: one,two to one,two,three

In TapeApp activities it says:
added: one
added: two
added: three

Any ideas?