Unity Project Browser History Buttons
Back and forward buttons for the Unity project browser
Only works in Two Column Layout (not the skinny layout).
Tested in Unity 2018.2.14 with .NET 4.x scripting runtime. Previous/future versions may or may not work depending on how much Unity changes their code.
Download the two cs files and put them in an Editor folder.
Example: in "Assets/GreatFolderName/AnotherFolder/Editor/"