function getValueLookup(obj, part) {
  if (part === '$*' && obj instanceof Map) {
    return obj;
  }
  let _from = obj?._doc || obj;
  if (_from != null && _from.isMongooseArrayProxy) {
    _from = _from.__array;
  }
  return _from instanceof Map ?
    _from.get(part, mapGetterOptions) :
    _from[part];
}
Return the value of `obj` at the given `path`.

@param {String} path
@param {Object} obj
@param {Any} map