You have the ability to control the levels of the Genealogy that you would like to display on the extranet.
Click Company tab, Extranet Setup.
Click Genealogy.
From the dropdown, select the appropriate Upline and Downline level that you would like for your distributors to be able to see, If you prefer the unlimited # function, you can select the checkbox to indicate so.
Genealogy can be viewed from the Reports tab in the extranet.