[{"myLocalizedField":[{"k":"en","v":"Hello world"},{"k":"de","v":"Hallo Welt"},{"k":"cz","v":"Ahoj světe"},{"k":"es","v":"Hola Mundo"}]},{"myLocalizedField":[{"k":"en","v":"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."},{"k":"de","v":"Da ist niemand der den Schmerz an sich liebt, der danach sucht und ihn haben möchte, einfach weil es Schmerz ist..."},{"k":"cz","v":"Nikdo nemiluje bolest samu, nevyhledává ji, ani ji nechce získat, protože bolest..."},{"k":"es","v":"No hay nadie que ame el dolor mismo, que lo busque, lo encuentre y lo quiera, simplemente porque es el dolor."}]}]

db.collection.aggregate([{$match:{"myLocalizedField":{$elemMatch:{"v":{$regex:"llo"}}}}},{$unwind:{path:"$myLocalizedField"}},{$match:{"myLocalizedField.v":{$regex:"llo"}}}])