I could not find anything on Google, I thought id try here.

I have a program that will look in a specific directory the user selects (Lets use the Desktop for example)

Now, this user can see everything on their desktop from this program, in the form of a listbox.

Now, lets say this person has a folder on the desktop called "aaaa" and inside that "bbbb" and inside that, "ccccc".

They want to go inside aaaa, so they doubble click on the folder "aaaa" from the listbox.

Now, lets say they navigate into bbbb, and they want to go back out into aaaa from the program, they would press the "back" button instead of the "forward" button.

My question is: How exactly is a "back" and "forward" button constructed?
Right now, all I could figure out, is how to navigate them to 1 folder up, so if there on the desktop, then I can have it navigate them to aaaa, however, if they try to click on bbbb, the program will try to go to the desktop, and proceed 1 lvl up, which would be aaa, so it will crash.

IO.Directory.GetDirectories(My.Computer.FileSystem.SpecialDirectories.Desktop & "/" & Listbox1.SelectedItem)