Of course, zillions of sphere brushes can be created within Affinity Designer (as well as many other designs using exactly the same approach). This makes a globe in a basic way, another great way of creating a globe is to use a 3D application and generate the result as a PNG file and then import that into the application or perhaps use Illustrator and their excellent vector 3D features.
To start, select the ellipse tool and make a circle by holding down the shift key.
Go to the fill panel and then click on the gradient tab and fill with a gradient. Go with elliptical type and set the stops color and the mid point for that resource. Go to the gradient tool and apply and set a lovely highlight on the circle (using white as the first stop). You can position it in multiple ways but it probably works best with having the highlight on the top left of the circle.
Go to the file and export and save it as a PNG format file as I want to import it later. You can go for the whole document or selection.
Go to the brushes panel and you can find that in the view menu and studio. Go to the right side menu of the panel and select the new textured image command. Select the saved PNG file.
Select the resource in the panel. Go to the vector brush tool and apply and you can see your design stretched.
You can double click the entry and edit the settings and go to the body entry and select 'repeat'. Change size and size variance etc. Go to the bottom of the panel and change the red dots boundary for the existing stroke, place them closer to get more of the design than the background. As you change it, you will see the preview change but you can still continue to test your stroke using the current tool. Apply your new stroke and test.
You can also re-color the design by using adjustment layers