I was so hopeful for this to work! I tried both but it's still not pulling in the parameters.

function onLoad() {
    g_form.setMandatory('model_id', true);

    var glideURL = new GlideURL();
    glideURL.setFromCurrent();
    var comp = glideURL.getParam("sysparm_Comp");
    var CI = glideURL.getParam("sysparm_CIname");

    if (comp) {
        g_form.setValue('company', comp);
    } else {
        g_form.addInfoMessage('test' + CI );
    }

    var url = top.location.href;
    var comp2 = new URLSearchParams(url).get("sysparm_Comp");

    if (comp2) {
        g_form.setValue('company', comp2);
    } else {
		g_form.addInfoMessage('msg2 ' + comp2);
    }


}

nav_to.do?uri=%2Fcmdb_ci.do%3Fsys_id%3D-1%26sysparm_view%3Dcontract_management%26sysparm_view_forced%3Dtrue%3Fsysparm_CIname%3DNETAPP%2520PARTNERCHOICE%25204HR%2520PARTS%2520REPL%2520AND%3Fsysparm_Comp%3Dec251e202b3bb0002918764317da157b

I'm attaching the info messages which show no value is getting picked up. You can see in the url that sysparm_CIname adn sysparm_Comp are being sent