Emulator

What's the problem? Describe what went wrong.

Unknown value search was a feature found in older versions of Dolphin. It is needed for creating codes when the user does not know what value they are looking for.
It was previously found in the the drop down that contains 'equals to' and such, but is now missing.
Leaving the text box blank and starting a new search with 'equals to' will result in getting the same number of entries as entering 0.

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.

Yes, 5.0-8937

Is the issue present in the latest stable version?

No, this feature still existed in 5.0.