When you try to view the imodel file in eB web by selecting the option 'Display in Visual Navigator' you cannot find the project explorer tab. To enable the project explorer follow the steps below.
Step1
Select and right click on DNC Control file using notepad which is located at C:\inetpub\wwwroot\<webroot>\PlugIns\VisualNavigator
Step2
Search for blue highlighted part as shown in below screenshot.
Step3
Change the required true false values accordingly and save it as shown in below screenshot.
<param name="GraphicsOnly" value="false" /><param name="ProjectExplorerExpanded" value="true" /><param name="AlwaysHideStatusBar" value="false" />
Step4
Now when you will try to view the i-model file in eB web using option 'display in visual navigator' you can see the project explorer tab.