Windows commandline: move all subfolders' contents to parent

You can't do a move * .. for directories. The only way for move to move a directory is to specify the directory name itself (no wildcards allowed). So you need a second loop (within the first) to loop through the directories:

@echo off
for /d %%d in ("*") do (
  for /d %%e in ("%%d\*") do (
    move "%%e" .
  )
)

No need for pushd because you can move it from the parent to the parent.

note: this is used for a batch file so for the %d the % is doubled to %%d and %%e. If you run it directly from the prompt you only need one %.

Edit:
If the first-level subfolders (Subfolder1 and Subfolder2) also contain files (besides folders Stuff1 and Stuff2) you can add another move to the outer for.

@echo off
for /d %%d in ("*") do (
  for /d %%e in ("%%d\*") do (
    move "%%e" .
  )
  move "%%d\*" .
)