Here is this dict.cc entry that i stumbled across, it appears to be wrong, to my knowledge that should be:
1) Das hätte gemacht werden müssen – That would have had to have been done (but it wasn’t)
2) Das müsste gemacht worden sein – That would have had to have been done, was bound to have been done before xyz time, in order for something to be the case.
so what is dict.cc's 3) "etw hätte gemacht worden sein müssen"... Is this correct? is this another tense?
I think maybe it is wrong.
Unless this is correct and the difference between 1) and 3) would be perhaps:
1) That would have had to have been in the process of being done
3) That would have had to have already been done, before xyz happens
So whats the difference in the german phrases: "das hätte gemacht werden müssen" and "das hätte gemacht worden sein müssen"