You can add custom map layers to Focus 360 and the Analytical Toolbox by following these steps:
Prepare your file in GeoJSON format.
Use WGS84 as the map projection.
Give the file the name you want to appear in the Focus 360 legend.
Check your GeoJSON file by uploading it to https://geojson.io first.
Upload the GeoJSON file to the Sensing Clues Upload Service (Premium service).
The map layer will be available in Focus after 20:00 GMT.