You got it so $('node-name').all() will return all output items from a node, If you wanted the first item you could use .first() and for the last item it would be .last().
If the node is following the node you want the output from you can just use $json.x then the auto looping will kick in but if it is 2 or 3 nodes back and you want to use the inbuilt looping for items you would use $('node-name').item.json.x