Original color buffer

Hi. How do you access in reshade 4.x a sampler with the original color if you need it in a shader?
In reshade 2.x it was something like tex2d(ReShde::Originalcolor, texcoord.xy) but I don't know if there's something similar in reshade 4.
Any help would be appreciated.
Thanks.

You need to write it out to a texture in a first pass and then use that texture when necessary in subsequent passes.

Take a look a Splitscreen.fx - It does exactly that.