4 eyes principle: I would like to write a JQL filter where check the 4 eyes principle

[Mees]

I would like to write a JQL filter where I see wich tickets have been tested by a different assignee than the assignee that built the story: 

Example:
Ticket 1, built by person A, tested by no one.  (NO) 
Ticket 2, built by person B, tested by A.  (YES)
Ticket 3, built by person C, tested by B.  (YES)
Ticket 4, built by person C, tested by C.  (NO)

Result: ticket 2& 3 

[Jack Brickey]

it sounds like you are looking for where the Reporter != Assignee. Is that correct? Unfortunately JQL doesn't support that OOTB. You might be able to leverage automation and custom fields to achieve your goal. Or consider a scripting add-on.