If you use
dired-aux, which is built-in in Emacs and you can easily require in your init file, you can then press i on a directory in a Dired buffer and have its contents displayed in the current buffer.
dired-maybe-insert-subdir. As per the documentation (C-h k i):
Insert this subdirectory into the same dired buffer.
If it is already present, just move to it (type M-x dired-do-redisplay
to refresh), else inserts it at its natural place (as ls -lR would
have done). With a prefix arg, you may edit the ls switches used for
this listing. You can add R to the switches to expand the whole tree
starting at this subdirectory. This function takes some pains to
conform to ls -lR output.
If you do C-u i in the parent directory, you will see all the sub-directories in the buffer. In your example, move up one directory, press C-u i on
TEMP and add the