Criteria.scala

  @tailrec
  private def criteria(
      baseCriteria: Criteria,
      criteriaList: Option[Criteria]*
  ): Criteria = {
    criteriaList match {
      case head :: tail =>
        criteria(
          head.fold(baseCriteria) { criteria =>
            baseCriteria.copy(startDateTime =
              criteria.startDateTime.orElse(baseCriteria.startDateTime)
            )
          },
          tail: _*
        )
      case Nil => baseCriteria
    }
  }

case class Criteria(
    startDateTime: Option[LocalDateTime],
    endDateTime: Option[LocalDateTime]
) {
  def updateHierarchically(hierarchy: Seq[Option[Criteria]]): Criteria =
    Criteria.updateHierarchically(this, hierarchy)

  def update(criteria: Criteria): Criteria =
    this.copy(
      startDateTime = criteria.startDateTime.orElse(startDateTime),
      endDateTime = criteria.endDateTime.orElse(endDateTime)
    )
}

case object Criteria {

  @tailrec
  private def updateHierarchically(
      baseCriteria: Criteria,
      criteriaList: Seq[Option[Criteria]]
  ): Criteria = {
    criteriaList match {
      case head :: tail =>
        updateHierarchically(
          head.fold(baseCriteria) { criteria =>
            baseCriteria.update(criteria)
          },
          tail
        )
      case Nil => baseCriteria
    }
  }
}