You can find the Affinity Designer node tool in the tools panel.
Works with paths, objects such as rectangles and ellipses etc need to be converted to curves before you can modify the path's shape. You can use it with open and closed paths in the application. You can also use it with type.
Click on a point (square - sharp point as well as circle point - smooth) as well as the edge of the path as well. You can click on the path and create a new point but you can also select and drag on the path (or points) to reshape the vector design.
Many options are available such as the ability to convert the selected point to a sharp point or to a smooth point as well as the ability to make a smart point for the best fit. You can also use the control bar features to break the current path as well as to join two path as well as close an open path and also reverse a path. You can also smooth the curve so all the points bar a couple are turned into smooth points and you can then go to the sharp ones and select and turn them into smooth as well
You can manipulate the points but you can also manipulate the handles, hold down the alt / option to break the link between the in and out (left / right) handles and stretch and squeeze the handles to distort or smooth the path.
You can select a point and press the delete key to delete it
Click on the path to add a new point which can then be manipulated.
Select a point on the path, any point and then go up to the actions in the control bar. Select the first action and that is to break curve. Click that and instead of an closed path or a single open path, you will get two separate open paths. You can then move the points for those paths separately. You can also select all the points on a path and then apply the same command and if you have a path made up of 50 or so points then you will end up with 50 entries in the layers panel which can then be manipulated separately such as changing the color of the lines as well as the pressure profile as well as other settings or they can be deleted etc.
You can use it to drag the selected part of the path as well. Just select the line you want to drag and you can move it left or right or up and down. If you actually click it, it will create a point on the line but the act of selecting it and dragging does not generate an additional point. It will just change the handles of the two adjacent points to create lovely smoothed design. If it is a curved line and a point is added, it will be a smooth point but you can go to the convert in the control bar and click the shape option. You can go around the entire shape and drag in and out all the path to create a distorted wavy design in seconds. If you add lots of points to the path, you can then select in between them and create lots of smooth ripples to the vector line.
You can select all the points and then use it to reposition the entire shape but if you use the drag and select approach for a couple of points and leave some unselected then you can drag the curves in and out to create all kinds of unusual distortions of the vector artwork.
You can also use it with type but to do this you need to click the convert button or select the command when you right click a path. The path can then be modified in the same way as a rectangle or vectors created by the pen etc.