This optional field is used to define the number of levels to search within a site to find lists for the SharePoint Data Provider display. If this field is left blank, it will default to 0, which searches only the site named in the Site URL field. The maximum recommended number of levels is 10.
Please make sure that a number is entered in this field. If you spell out a number, it will result in an error and no lists will be found.
If you have chosen the Selective return type and you change the value identified in this field, click the "Refresh Available Lists" option to the right of this field. This updates the sites and lists identified in the Available Lists drop-down field, described below.