Download Categories on Homepage
The download categories are displayed using 4 instances of the Custom Menu widget.
First, you will need to head to your Menus page (Appearance > Menus) and create 4 custom menus. We titled them Cats 1, Cats 2, etc. In each of these menus, add your download categories from the list on the left:
Once you've finished building and saving your 4 menus, head over to the widgets page (Appearance > Widgets). Drag 4 copies of the Custom Menu widget into the Home widget area. In each of those individual widgets, you can select your 4 custom menus that you created in step 1.
Save your changes and you should be all set.