I think I read it to fast, what you do isn't "dot-walk". Since Dot-walk usually means that you go to another record. Like if I have a incident record as current I can type current.caller_id and I'm not dot-walking, but current.caller_id.email is. Since then I need to go into the caller record to get the email address. The caller_id value is on incident. 

But your problem seems strange. if you use getDisplayValue, does that work?

Where exactly do you want me to try getDisplayValue?  I notice when I try to search for incidents with the u_service_level = 3 I get the following in the encoded query so I'm not sure if there is special scripting I have to do for this or it will not work.

cmdb_ci.ref_u_cmdb_ci_myclass.u_service_level=3

Ahh that is probably the reason, you are using getReference on a field that is reference to the cmdb_ci table. And the field you want to get isn't on that table, but on an extended table. That means that when you query the record from cmdb_ci, you won't get back that field, only the field that exist in the cmdb_ci table.

That is what I figured but just wanted to see if there was a way to do it.