https://docs.unity3d.com/es/2019.1/ScriptReference/Handles.Slider2D.html
Handles-Slider2D - Unity Scripting API
Make a 3D slider that moves along a plane defined by two axes.
handlesunityscriptingapi
https://docs.unity3d.com/ScriptReference/Handles.Slider2D.html
Unity - Scripting API: Handles.Slider2D
scripting apiunityhandles