Its called "Show Shaded Material in Viewport". Whatever texture you have selected you press this button and you see that in the viewport instead of the entire material.
But it doesn't really matter the name, its just some arbitrary reference to the inbuilt function in the 3D software. My point is: every plugin in 3dsmax can use these built in functions, so if cinema4d doesn't have this and its reliant on the engine then, well that sucks lol. I'm not bashing on cinema4d by the way, I think the software is actually pretty amazing, I do some scripting these days in it so I'm using it more but yeah, some of the hierarchy stuff is totally weird to me.
Don't quote me on this but I'm not sure if that applies to fstorm, I dont use it. But from what ive read from users lots of stuff is quite unique in fstorm materials compared to 3dsmax general input so maybe fstom does things different, just putting it out there incase I'm not covering all bases. Redshift, Octane, Corona, Vray, Arnold, Mental Ray, Standard all have access to this feature in 3dsmax, that's about the extent of my experience.
