Routable modal to cover detail area of master-detail display

In a master detail display on a wide screen the master page is on the left and the detail page on the right.

When I open a SmartSelect in the detail page in only covers the detail page. When I open a routable modal from within the detail page it covers both the master and the detail pages. I want it to be like the SmartSelect and to only cover the detail page. The routable modal can be a sheet or popup.

Found the answer: containerEl