Excluding elements from the model helps to demolish elements and element hierarchies that are not relevant for anyone. Doing this will hide the element from rule checks, dependency insights, model comparison, Impact Report visualization and Softagram Desktop use cases. However, if you just need to exclude the elements from visualizations only, and keep them available for other things, such as rule checking, then see http://help.softagram.com/en/articles/3837900-excluding-elements-from-impact-report-visualization
Here are the steps for exclusion:
Figure out your project ID. Project ID is a UUID type of ID and can be fished easily from Softagram web as the URL easily shows it while navigating to project specific view. Figure also out what is the project name. If using Softagram Desktop, you can find from the model root element that is named according to the project..
Run command (replace first PROJECT_ID and PROJECT_NAME)
docker exec -ti softagram python3 ui/cli/softagramservice.py update_project_settings --project-id PROJECT_ID -s "analysis.postprocessing.remove=/PROJECT_NAME/External"