As a Global Administrator, you can track all changes made across your organizations using the Audit Logs in the Global Admin Console. Sign in to the Global Admin Console and navigate to Insights > Audit Logs.
You can do the following to filter the audit logs:
Search events by the affected user or the admin who performed the event.
Define a date range.
Select an event name.
Select an organization.
Also, if the organization that you are viewing the logs for has a child organization, actions taken by a System Admin in the child organization are also included in the audit logs. Audit Log data is retained for 90 days. You can search through the log, as well as export the data to a CSV file.