Embedded dashboard with dashboard Level filtering in URL

I have a dashboard that uses a dashboard level filter called Account. I created an external share link yet I can’t see that dashboard level filter when I access the dashboard through the external link.

Also, I am trying to manipulate the filter (the dashboard level one which I can’t see) or the other 6 filters on the dashboard through the URL and am not getting anywhere.
I tried adding ?p_accounts=MYACCOUNT but it seems to not do anything both on the original URL and on the share URL.

The external share URL looks like this /public/dashboards/xxxxxxxxxxx?org_slug=default.

Any help is much appreciated.

What kind of parameter is this? Text type params are disabled for public dashboards.