No, it can"t be interpreted in such a way. Even if "kenyérkereső" is equivalent to "breadwinner". But when intended to be used with that meaning, the determined conjugation ("tárgyas ragozás") is required instead of the indetermined conjugation ("alanyi ragozás"). In this case, the verb "keres" is conjugated indeterminedly, so the literal meaning has to be used. The determined conjugation would be "keresi". (More on this in the reply to this comment.) (Mastering the correct usage of these two conjugation types is probably the most challenging verb-related obstacle for aspiring speakers of Hungarian language, at least for those with an Indo-European background.)
In order to illustrate the two conjugations, let"s take the following sentences: "Péter kenyeret keres.", "Péter keresi kenyerét."/"Péter kenyerét keresi". In the sentence "Péter kenyeret keres." the indetermined conjugation is used, and this sentence just means that Péter is looking for (some kind of) bread. (A general, non-specified object.) But in the sentence "Péter kenyerét keresi.", the determined conjugation is used, in which the verb requires a determined, specified object. This latter sentence literally means "Péter is looking for his bread." and will be translated to English as "Péter is earning his bread". More about the Hungarian conjugation types: https://myhunlang.com/2010/02/07/the-difference-between-definite-and-indefinite-conjugation/ https://hungaryforyou.wordpress.com/2013/03/16/conjugation/ https://hunlang.files.wordpress.com/2013/09/summary_for_hungarian_verbs1.pdf
Honestly, I'm starting to think you are a troll. You seem to have some idea about how things works and mix them up in theoretically meaningful but nonexistent ways.
(...) Jó kenyeret keres (...) is grammatical, no matter the context, later you bring up possessional sentences that are indeed treated definite but have nothing to do with the given sentence.