changing ‘where’ for a form

Hi,

For the internal website of my organisation, I love to work with the forms of pods. I would like to change the form a bit depending on the user who is logged in.

I would like to change the ‘where’ of a relational field in a form with php. How do I do that?

I see you can change some options for a specific field in a form.
On the (information page about forms on pods.io I can find the following options you can change: type, label and default. What more options do you have to make changes? Could someone give examples of every option? So I know more what the possibilities there are. And especially how does it work to change the ‘where’.

Here the example code I’m refering to on the information page:
$params = array( ‘lightsaber_color’ => array( ‘default’ => ‘green’ ) , array( ‘sith_or_jedi’=> array( ‘default’ => ‘jedi’ ) ) );
echo $mypod->form( $params );

Thanks