Uses Lodash 'pickBy' to omit properties whose keys do not match those we've specified.

LodashPickByToOmit.ts

const omit = (originalObject: object, keys: string[]) => _.pickBy(objectFromFrontend, (value, key) => !keys.includes(key))

const objectFromFrontend = {
  _id: 5,
  data: {
    some: 1,
    useful: 2,
    data: 3
  }
}

const objectToInsertIntoDB = omit(objectFromFrontend, ['_id', 'data.some']);

console.log(objectToInsertIntoDB)
/**
* {
*   data: {
*    some: 1,
*    useful: 2,
*    data: 3
*  }
* }
*/

console.log(objectFromFrontend)
/**
* {
*   _id: 5,
*   data: {
*    some: 1,
*    useful: 2,
*    data: 3
*  }
* }
*/