type Node = ref object of RootObj id: string Container = ref object of Node scope: seq[Node] View = ref object of Node name: string initNode: Node scope: seq[Node] let first = Node(id: "InitNode") other = Node(id: "Hi") container = Container(scope: @[Node(id: "Node1"), Node(id: "Node2")]) # It is necessary to cast to Node here if you initialize a seq like this view = View(name:"View1", initNode: first, scope: @[container.Node, other]) proc forEach(node: Node) = if node of Container: let c = Container(node) for node2 in c.scope: forEach(node2) elif node of View: let v = View(node) forEach(v.initNode) for node2 in v.scope: forEach(node2) else: echo "Node id: ", node.id forEach view