Find list of CDT/record types in the application that uses specific data type

Export all CDTs and check the XSDs.

If you can find a way to get the list of CDTs, you could do this

a!localVariables(
  local!CDTList: {
    'type!{urn:com:appian:types:S}S_COM_35103'()
  },
  a!forEach(
    items: local!CDTList,
    expression: a!localVariables(
      local!CDT: fv!item,
      local!CDTTypeName: typename(typeof(local!CDT)),
      local!keys: a!keys(local!CDT),
      a!forEach(
        items: local!keys,
        expression: a!localVariables(
          local!field: fv!item,
          local!fieldType: typeof(index(local!CDT, local!field, null)),
          local!fieldTypeName: typename(local!fieldType),
          if(
            local!fieldType = 9,
            a!map(
              entityName: local!CDTTypeName,
              fieldName: local!field,
              fieldType: local!fieldType,
              fieldTypeName: local!fieldTypeName
            ),
            {}
          )
        )
      )
    )
  )
)