Adding Utill Function in Report Designer

I believe you will need:

using PX.Data.BQL;

and/or possibly:

using PX.Data.BQL.Fluent;

already i use that reference, i attached my source.

Ok, I see now that the issue is not that you're missing a reference. It's that you're either not using the function correctly, or Visual Studio doesn't know what the objects are that you're using in the function. Are you trying to compile or publish?

If you're trying to compile, you'll obviously need to resolve the errors before that can happen, but if you're updating the package through the Visual Editor, you can attempt to update and publish and see if the issues persist.

yeah i trying to compile

Is this code you wrote? I've not seen select statements written quite like that before. I'm curious where you got the format for them.

i decompile the dll, then show that code

In that case, I suggest you rewrite the selects. I believe that will resolve your issues.

Decompilers are not a great place to learn to write code.

okay i will try now