How to using double for_each in terraform?

everyone.
While using for_each in terraform, duplication is coming out. In this case, how should I bypass it?

The problematic points are 1), and 2). data values must be obtained from each resource through for_each.

// custom hostname binding
resource "azurerm_app_service_custom_hostname_binding" "service_host_bind" {      
  for_each                     =  azurerm_dns_cname_record.cname_target       
  hostname                  = trim(each.value.fqdn, ".")       
  app_service_name     = azurerm_app_service._service.name       
  resource_group_name = azurerm_resource_group._rg.name       
  depends_on          = [azurerm_dns_txt_record._txt_target] 
  lifecycle {         ignore_changes = [ssl_state, thumbprint]       }    }

// app service managed certificate
resource "azurerm_app_service_managed_certificate" "_service_manage_cert" {       
      for_each                    = azurerm_app_service_custom_hostname_binding._service_host_bind       
      custom_hostname_binding_id  = each.value.id          }

// app service certificate binding
resource "azurerm_app_service_certificate_binding" "xtrm_service_certi_bind" {       
      1) hostname_binding_id = azurerm_app_service_custom_hostname_binding._service_host_bind.id       // ## how to for_each??
      2) certificate_id               = azurerm_app_service_managed_certificate._service_manage_cert.id         // ## how to for_each??
      ssl_state           = "SniEnabled"            }