Sub category list

I already asked this question, but could not solve the problem, so I ask here again. I want to make list as follows, giving indent to differenet level of category. However, indent / markdown / tab+indent did not work in my case.
Even though I indent in the post draft, if I publish the post, indent disappears.
Is it possible to do as follows without coding/CSS/editing code injection?

(60)
(61)
INDENT(a)
INDENT TWICE(i)
INDENT TWICE(ii)
INDENT(b)
(62)

I’m not sure about (60) style but normally you can use nested bullets easily by just

1.{SPACE}Text
{TAB}Text
{TAB}{TAB}Text

Result would be something like: