how to add multiple aws routes to multiple aws route tables

Question

To avoid creating multiple aws_route resources. I am trying to add multiple destination_cidr_block from a map to multiple route tables. I think I am in the right direction, however, it is only adding a few cidr blocks from the list to each route table and not all cidr blocks to each route table.

variable "destination_cidr_block" {
          type = map
          default = {
            destination_cidr_block = {
                 private = [
                   "0.0.0.0/0",
                   "0.0.0.0/0",
                   "0.0.0.0/0",
                   "0.0.0.0/0",]
                 private1 = [
                   "0.0.0.0/0",
                   "0.0.0.0/0"]

resource "aws_route" "private" {
  count = local.length_of_rt_cnt
  route_table_id         = element(module.private.private_route_tables_id, count.index)
  destination_cidr_block = element(var.destination_cidr_block["private1"], count.index)
  gateway_id =     module.vpc.id
}

How can I get all routes from private1 to the the multiple route tables that are already created from this module.

I apologize, everything has been destroyed and I did not saved the error. I know accomplishing multiple route tables with on destination cidr block which would look like this.

resource "aws_route" "private" {
  count = local.length_of_rt_cnt
  route_table_id         =  element(module.private.private_route_tables_id, count.index)
  destination_cidr_block = 0.0.0.0/0
  gateway_id =     module.vpc.id
} 

In this case 4 route tables will receive this cidr block. Now the question is how can I add a list of cidr block to a list of route tables