If you want to reproduce Blender’s appearance using Filmic in other software, you have to make sure that you’re using the same order of operations.
Basically, everything has to be done on Linear (more specifically linear rec.709) and the result will go through an OCIO transform. Remember that Blender applies Filmic as a “view” transform, meaning that it’s just applied on top of the compositor/render output for viewing purposes.
So, in order to fix your scene:
- Load the linear EXR as-is, don’t apply any transforms. Data will stay in the original linear rec.709 colorspace.
- Composite the passes
- Put an OCIO transform only before the media-out Node, from Linear to Filmic (if you used other than base contrast in Blender for your reference you’ll have to use the FIlmic All-Views config from @troy_s as Fusion/Resolve don’t support OCIO looks.)
As a rule of thumb, always do your compositing on linear. Only move to display-referred data when you need to (that’s usually as a view transform for viewing or for final delivery to a display).