I'm trying to create a flow diagram(usingFlow Map Viz) with couple of nodes and want to draw a node to show grouping of couple of nodes(kind of like a boundary box with less opacity). I can see that the 'boundary box' node in some cases lies on top of the other nodes and in some cases the other nodes lies above the boundary. Noticed this because when you mouse over the node, instead of the node tooltip, I see the tooltip of the boundary box.
Is there a way to ensure that the boundary box node lies below all other nodes? Ie. Ensure correct order of layer