Remove dagger generated classes from Android Studio's global search?

If you are talking about the generated MembersInjector and Factory classes:

MyClass_MembersInjector.java
MyClass_Factory.java

you can prevent these from coming up in the Ctr-N or Cmd-O dialog by adding them to the ignored files list in File / Settings / Editor / FileTypes and adding the appropriate wildcards to the Ignore files and folders edittext:

*_MembersInjector.java; *_Factory.java; will cause most of the generated classes to be ignored:

Before:

After:

You can even add Dagger*.java to the list if you don't even want to see the generated component (even though this is rather useful for the project).

Update:

If you are talking about not having the classes appear in auto-import/auto-complete this is done through Settings / Editor / General / Auto Import:

David Rawson's answer doesn't help to get rid of not showing _Factory classes when performing Find Usages on the class name. This is what will be shown:

This can be resolved with creating a new scope which will disregard generated files.

Here's the regex for generated files in app module: !file[app]:build/generated//*. But you may as well use "Exclude recursively" button locating the directory you want to get rid of.

Now, change the search scope to newly created:

And this will be the output:

No _Factory classes. You may as well get rid of classes in test packages, thus only classes from production package will be found.