Just recently, I have been experimenting with Revit Construction Phases and noticed that they were not showing up in Navisworks. Scott Johnson from our TS Construction team has run into the same issue and offered this solution:
Make sure your Global Options in Navisworks have the Interface-->Selection-->Resolution set to 'First Object'. Note the Import and Export buttons - these allow you to save your settings to share with others!
With the Global Options set correctly the Revit Phase options now show in the Navisworks Properties tab.
The Find Items tab in Navisworks can be used to locate building objects based on Revit Phases. Navisworks selection sets can be created and associated with TimeLiner to link to construction schedules. Once links are established, TimeLiner give us the ability to show what a project will look like at specific dates according to the project schedule.