write custom expression for grouping in record type

Here I want to get the most visited top 3 destinations and the count of journeys on each location.(relationship between 2 tables) So make an expression rule for that. but I need to do with record type with the use of a custom record field, here i found the custom expression rule, anyone guide me on how to use this code with a custom expression rule in record type? code below here

a!localVariables(
  local!data:a!queryRecordType(
  recordType: 'recordType!{64a0e01d-65e7-493d-8373-98dd241cb809}VS Journey',
  fields: a!aggregationFields(
    groupings: {
      a!grouping(
        field: 'recordType!{64a0e01d-65e7-493d-8373-98dd241cb809}VS Journey.relationships.{324614a4-84f3-45b4-bce2-95cbc8b65b6d}vsDestination.fields.{dbe0e7f1-b3d7-456b-9d82-e81a9042d256}name',
        alias: "name_grouping1"
      )
    },
    measures: {
      a!measure(
        function: "COUNT",
        field: 'recordType!{64a0e01d-65e7-493d-8373-98dd241cb809}VS Journey.fields.{1209585a-f527-4ad9-b1fc-cc7ccc5dd973}destinationId',
        alias: "destinationId_count_measure1"
      )
    }
  ),
  filters: a!queryLogicalExpression(
    operator: "AND",
    filters: {
      a!queryFilter(
        field: 'recordType!{64a0e01d-65e7-493d-8373-98dd241cb809}VS Journey.fields.{75d3137b-b408-4bcb-8c31-ac2fd13e123a}customerId',
        operator: "=",
        value: 4
      )
    },
    ignoreFiltersWithEmptyValues: true
  ),
  pagingInfo: a!pagingInfo(
    startIndex: 1,
    batchSize: a!defaultValue(value: 3, default: cons!VPA_DEFAULT_BATCH_SIZE),
    sort: {
      a!sortInfo(
        field: "destinationId_count_measure1"
      )
    }
  )
),
/*cast(194,local!data.data)*/
if(
  ri!returnDataSubset,
  local!data,
  if(
    local!data.totalCount > 1,
    cast(194,local!data.data),
    index(local!data,1,null)
  )
),
)