Unable to click on hologram level to view imperial objectives after moving under construction imperial level

_{Answer derived from previous comments (now deleted):}

This is generally just a display bug, the level is actually an Imperial Level despite the name.

You should try closing the game and reopening it. This often fixes similar display issues.

Unfortunately, Tiny Death Star has been discontinued:

The game was removed from the Apple App Store and Google Play Store by Disney in October 2014.

If you are unable to workaround the bug/issue by restarting the application or your device, then there's nothing we can do: there is no fix coming.

As you are playing on iOS, I would not recommend uninstalling the game if you wish to keep it. Only those who had previously downloaded the game on Android can still redownload & access the game.