Remove 'up to third occurrence of /' from a string?

[troy]

How would I remove up to the third occurrence of the / in the following string:
/Users/troykrueger/Dropbox/MDA/Numbers/Exports/Thu, Jul 5, 2018 3-04-43.csv

to end up with:
Dropbox/MDA/Numbers/Exports/Thu, Jul 5, 2018 3-04-43.csv

I can do it in FMP, and I know it's in KM, I'm just not coming up with the simple solution.
Thank you~

[ComplexPoint]

One approach:

(() => {
    'use strict';

    const
        fp = Application('Keyboard Maestro Engine')
        .getvariable('filePath');

    return fp.split('/')
        .slice(3)
        .join('/');
})();

[peternlewis]

Easily done with a regex search and replace ^/(.*?)/(.*?)/:

Keyboard Maestro Actions.kmactions (758 B)