@psychicparrot42 It's an editor plugin called 'Electronic Nodes' https://www.unrealengine.com/marketplace/en-US/product/electronic-nodes
I really highly recommend it if you're doing anything blueprinty. I find it *massively* improves readability, and it works in all the blueprint editors - actors, widgets, materials, etc.
My only real complaint with it is that it can result in some overlapping unless you place extra nodes. Would be nice if it auto-routed to minimise overlap - but overall, it's awesome.