Select a single tracker Null that is horizontal in respect to
the source material (what you tracked in AE).
Like the Green or Blue one in your scene I’d guess.
Copy it to -outside- of the hierarchy,
rename the copy to something useful (like “New Zero”).
Set its rotation order from ZYX to HPB (for sanity reasons)
But keep all values as is right now!
Drag the whole hierarchy, by dragging the top Null object
in under your “New Zero” null.
Your imported stuff is now a child of “New Zero”.
Now, nullify the “New Zero” Null by setting all
position parameters to 0,0,0. and
rotation parameters to 0,-90,0.
Additionally if you need to work in “real” scale in your scene
(i.e.for dynamics) first set all “New Zero” Scale parameters to 1,1,1.
Create an object with a known size compared to your footage
and scale your “New Zero” to fit.
Sounds much more convoluted than it is
Cheers
Lennart