[{"locale":{"en":{"dashboard":{"DASHBOARD_TITLE":"Some title"},"contact":{"CONTACT_TITLE":"Some title"}},"fr":{"dashboard":{"DASHBOARD_TITLE":"Some title french"},"contact":{"CONTACT_TITLE":"Some title FR"}},"pr":{"dashboard":{"DASHBOARD_TITLE":"Some title portugues"},"contact":{"CONTACT_TITLE":"Some title PR"}}}}]

/** lang just a refernce*/letlang='fr';db.collection.aggregate({"$project":{[`locale.${lang}`]:{"$arrayToObject":{"$filter":{"input":{"$objectToArray":`$locale.${lang}`},"as":"el","cond":{$eq:["$$el.k",feature]}}}}}})