How to manage RowList inside the another RowList?

Currently, I'm refering the VideoPlayer Channel Example. Which is Provide by Roku. In Example Second RowList content using First Rowlist URL. Does Anyone Suggestion How to call URL for open Second Rowlist in Roku?

sub OnRowItemSelected(event as Object)
m.grid = event.GetRoSGNode()
m.itemSelected = event.GetData()
m.rowContent = m.grid.content.GetChild(m.itemSelected[0])
m.ItemContent = m.rowContent.GerChild(m.itemSelected[1]) 
?"OnRowItemSelected - m.ItemContent : " m.ItemContent
end sub

'Below is the Response for the First Rowlist
OnRowItemSelected - m.ItemContent : <Component: roSGNode:ContentNode> =
{
change: <Component: roAssociativeArray>
focusable: false
focusedChild: <Component: roInvalid>
CATEGORIES: <Component: roArray>
URL: "pkg:/feed/anotherrowlist.json"
}

Does anyone know how to call another rowlist using this Response?