This article explains Downloading Analytics tab for internal use.
You can download a filtered report of tables from the Enrollments, Engagements, or Completions tabs by selecting "Download CSV" on the bottom right hand side of the specific data table. Use any of the filters (i.e. Start Date, End Date, Date Granularity, or Calculation Type) to hone in your data parameters.
For additional questions specific to Downloading Analytics data, please submit a support ticket to enterprise-support@edx.org, or reach out to your account manager (where applicable)