To reorder the sections in Discovery within your Mighty Network, navigate to Network Settings > Content > Organization and then to the section titled Discovery.
Use the drag and drop feature to reorder (or even hide) the sections that your members see when they open up Discovery from the left navigation.
Here's how it looks on mobile:
Are Events the lifeblood of your network? Show them off at the top! Want to make sure members can see which groups they can join? Drag the Groups section up to the top so that it’s the first thing members see.
You can rearrange the sections in Discovery as much as you like, as often as you like.