path = '.'
path = os.path.normpath(path)
res = []
for root, dirs, files in os.walk(path, topdown=True):
    depth = root[len(path) + len(os.path.sep):].count(os.path.sep)
if depth == 2:
    res += [os.path.join(root, d) for d in dirs]
dirs[:] = []
print(res)
List directories with a specified depth in Python