In the example I'm looking at "Simple Grid and Video" it has HomeScene.xml that has child components such as "GridScreen", an overhang, "Video".
You can create a new screen like this
newscreen = createObject("roSGNode","MyScreenComponent")
(of course you would need an XML and accompanying brs that defines your custom component "MyScreenComponent" as a full screen component, maybe extending Group)
then if it's created elsewhere, you need to pass that screen node to the HomeScene through a new field defined in HomeScene.xml:
<field id="myScreenNode" type="node" alwaysnotify="true" onChange="newScreenSet"/>
and have HomeScene append it as it's last child so it appears over top of anything on screen. in HomeScene.brs:
sub newScreenSet()
newScreen = m.top.myScreenNode
if newScreen <> invalid
m.top.appendChild(newScreen)
end if
end sub
aspiring