Summary:
Only one user detail is exported to IIF file, when using TimeSheet Export under Integration from QuickBooks Export even though All Users are select in the Filters.

Cause:
The Data to Export is selected as Map Client Name to Customer.

Resolution:
Change the Data to Export to Map Client Name:Project to Customer:Job will list the details of all the users.

Click on Settings under Integration > QuickBooks Export > TimeSheet Export
Select Map Client Name:Project to Customer:Job and Save the Settings.
Click on Generate if the details are not generated automatically.
Click on QuickBooks to export the file as IIF file.

Note:
The file exported will be saved on the computer according to the default folder with respect to the Web Browser used.