What is this Editor Slider called and how do I access it via code?

When Texture is select in the Editor, I can move this slider and change the image changes…What is that and how can I access that variable from script. I don’t need code. I just need link to the documentation.

Click here to see the slider I am talking about.

@Graham-Dunnett

This slider changes which mip-map of the texture you are previewing. This has nothing to do with editor/values, and instead is part of the engine’s texture importing system. If you wish to manually change the level of mip-map displayed on an object, you would have to write a custom shader and use functions such as tex2Dlod() when accessing that texture. It isn’t something you can strictly change through code, and is generally meant to be used to change texture quality when the camera is further away for performance reasons, although it can be used for interesting effects in shaders. Like SnStarr said, there’s no real documentation for this in regards to Unity, so you should do some research into the topic in general rendering.