Services Using views having search
If you try using filters via the UI on the page itself (not via a services endpoint request), check how the URL changes. If you are not using AJAX in your view, the URL should append all filter values to itself. Then in your services request (poster), try sending in that same URL pattern with the filter arguments in it.

For example, when I used a node title filter on my view and submitted it, I got this URL returned .../testpage?title=testfilter. Then try sending the poster request to this URL with the filter value of your choice.