I need to create a datadog synthetics monitors with the resource `datadog_synthetics_test`

I need to monitor multiples cluster, with multiple point of view :

    # Clusters
    variable "datadog_gke_clusters" {
      default = [
        # NPRD
        {
          name        = "cluster01"
          environment = "nprd"
          url = {
            private = "https://private.domain-priv.com"
            public  = "https://public.domain.com"
          }
        },
        # PROD
        {
          name        = "cluster02"
          environment = "nprd"
          url = {
            private = "https://private.domain-priv.com"
            public  = "https://public.domain.com"
          }
        }
      ]
    }

    # Point of views
    variable "gke_slo" {
      description = "Response time threshold in ms to respond to a request."
      default = [
        {
          zone              = private
          monitor_threshold = 50
        },
        {
          zone              = public
          monitor_threshold = 100
        },
      ]
    }

`for_each` need a map or a list of strings 

    resource "datadog_synthetics_test" "gke-monitoring" {
      for_each = ... # cartesian product of lists
    
      type    = "api"
      subtype = "http"
      ....
    }

There is a function `[setproduct(sets...)][1]` which produce a list which combine values of each list, but not a map.

I would need to produce a map which look like this : 

      {
        "cluster01-private" = {
          name        = "cluster01"
          environment = "nprd"
          url = {
            private = "https://private.cluster01.domain-priv.com"
            public  = "https://public.cluster01.domain.com"
          }
          zone              = private
          monitor_threshold = 50
        },
        "cluster01-public" = {
          name        = "cluster01"
          environment = "nprd"
          url = {
            private = "https://private.cluster01.domain-priv.com"
            public  = "https://public.cluster01.domain.com"
          }
          zone              = public
          monitor_threshold = 100
        },
        # PROD
        .... etc
      }

How could I do that ? 

  [1]: https://www.terraform.io/docs/configuration/functions/setproduct.html