Similar to the solution @vvaidya have already provided.
Every folder in Outlook have Folders collections.
We can modify his example to create folder inside Inbox.
“Assign activity” NewFolder = oFolders(“Inbox”).Folders.Add(“test”,Type.Missing)
Or we can create two of them for 2 level hierarchy
NewFolder = oFolders(“Inbox”).Folders.Add(“test1”,Type.Missing).Folders.Add(“test2”,Type.Missing)