There are two ways to change the display order of your subcategories.
Click and Drag
Hover your mouse over the six-dot icon to the left of the subcategory you want to move. Your mouse pointer will change to a four-sided arrow. Left-click and hold, then move your mouse up or down to change the subcategory's position. Release left-click to place the subcategory.
Placing a subcategory above or below another category will change their order. Placing a subcategory on top of a category will nest that subcategory within it. Click the arrow icon on the right side of a category to see its subcategories.
On the Categories page, click the grey View List button at the top right. On the Category List, hover your mouse over the Order column and click the blue Edit link.
Enter a number in the Order field to change its display order. A subcategory with a low number in the Order field will appear above a subcategory with a high number.
Click the blue Save button at the top right to save your changes. When you're done editing the Order field, hover your mouse over the Order column and click Disable Edit.