Browse contents of the VB Project.

xlCompare doesn't have Visual Basic editor like in Excel (You can open it by pressing Alt+F11 hotkey). So, there is no Project Tree and navigation a bit different.
All types of the VB Objects are on the View tab on the Ribbon
Ribbon - VB Objects
All types of objects you can select in the Project Tree in the Visual Basic Editor you can find here:
  • Object Modules (Sheet1, Seet2, ... ThisWorkbook)
  • Code Modules
  • Class Modules
  • Form Code
  • Form Objects
This works like a filter - you select Form Objects (like in this example) and all forms are on the tab strip on the bottom:
Visual Basic Forms on the Tab Strip
Browse Button [...] gives you complete list of the objects (Forms/Modules/Sheets).
Tab Strip - browse button
When you select Form\Modules it's contents is reflected in the xlCompare window.