Help with MD array with template...

I need some help with this problem with my array. I'm trying to display "complaints" listed by date.
I'm using this template -> ( https://ift.tt/3moKgWy )
I don't know how to loop inside a loop (or if it's possible with this template).

I'm still new to (and learning) PHP / MySQL How would you go about this?

Here's the relevant parts of the code. Let me know if you need more.

// Pull all the post to display
$sql = "SELECT *
        FROM complaint
        ORDER BY...

PHP:

Help with MD array with template...

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