Getting Invalid reference when searching with the data already present in the reference field

[SWAPNAG67418591]

see the above pic , i am trying to getting the data that is employee name from the employee table but I am not able to search with user first name, last name or email.
I am getting the error like invalid reference but when I search with the field employee id , I am not getting that invalid msg.

what should I do now? I need emoployee name in that field. 

[RaghavSh]

The reference field will only display the field which is marked "display=true" on table.

So example any reference field referring user table will show name as name is marked as display true(sys_dictionary).

if the screenshot you shared is OOB, I would not recommend changing the display value of that table. 

Please mark the answer correct/helpful accordingly.