Find two slash appearances in a field

How to search for cards that have two (or more) appearances of slash in one field?
Before slash there are spaces but this is less important.
I tried:
Field_name:* / * AND * / *
But it doesn’t work.

The case is that I need to separate those cards that have two slashes from those that have one slash.

Try "Field_name:* / * / *".
For reference: Searching - Anki Manual