Hello,
You can set “Custom content” in the “Shop filters content-type” and then add widgets into the Theme Settings > Shop > http://prntscr.com/qpf21y
In order to show the widgets from the Shop filter widget area http://prntscr.com/qpf2az in Appearance > Widgets please do the following:
1. Create HTML widget
2. Add the Widgetized Sidebar element and choose “Shop filters” sidebar
3. Choose the created HTML block in the “Shop filters custom content”
Best Regards