How to create sub directory?

[AFGreeneye]

I want to make a sub directory for "{channelname!C}" inside the "{author['username']!C}{subcategory!C}" but I don't know how! I tried to use "/" but it did not work.

{
    "extractor": {
        "kemonoparty": {
            "sleep-request": [1.0, 2.0],
            "metadata": true,
            "username": "xxx",
            "password": "xxx",
            "base-directory": "D:/XXX/Picture/Kemono/",
            "discord": {
                "directory": ["{author['username']!C}_{subcategory!C}/{channel_name!C}"],
                "filename": "{author['username']}_{subcategory}_{date:%Y.%m.%d}_{filename}.{extension}"
            },

[mikf]

Add another entry to the directory list.

"directory": ["{author['username']!C}_{subcategory!C}",  "{channel_name!C}"],

[mikf]

author['username'] isn't defined for kemono, by the way.

[AFGreeneye]

author['username'] isn't defined for kemono, by the way.

Well, it is what gallery-dl -K shows