How to use variable from parent page in drilled down page in scenes?

Grafana scenes
1

I have drilled down page from panel(parent page). Which has variable and being added in URL of child page (drilled down page).
e.g
service/api/metrics?var-service_name=abc

Now how do I use this in the child page? Ideally, I want to use this as a filter for my drilled-down page.

drilldowns: [
                    {
                        routePath: prefixRoute(`${ROUTES.Home}`) + '/service/api/:handler',
                        getPage: getHandlerDrilldownPage,
                    }
]

function getHandlerDrilldownPage(routeMatch: SceneRouteMatch<{ handler: string }>, parent: SceneAppPageLike) {
    // Retrieve handler from the URL params.
    const handler = decodeURIComponent(routeMatch.params.handler);
    console.log("api name is " + handler)
    let url = prefixRoute(`${ROUTES.Home}`)+ `/service/api/` + `${encodeURIComponent(handler)}`;
    console.log("url is = ", url);
    //console.log("service is = ", "${service_name}"); how do I do this ?
    return new SceneAppPage({
        // Setup particular handler drilldown URL
        url: url,
        // Important: setup this for breadcrumbs to be built
        getParentPage: () => parent,
        title: `${handler} endpoint overview`,
        getScene: () => getHandlerDrilldownScene(handler),
    });
}

function getHandlerDrilldownScene(handler: string) {
    return new EmbeddedScene({
        body: new SceneFlexLayout({
            direction: 'column',
            children: [
                new SceneFlexItem({
                    minHeight: 300,
                    body: topAPisPanel().build(),
                }),
            ],
        }),
    });
}

I want help with how do I access parent variables e.g user-defined variables, and time range in the child page.