Blocklist label get first element property from array object

Questions
,
1

Hi

I’m migrate Umbraco from version 13 to 15
In U13, for block editor item label, I just define {{country[0].name}} it will show me the first element of value
as the value of content
is
"[{\"id\":\"23\",\"name\":\"Spain\"}]"
where the detail is

{
  "contentData" : [ {
    "contentTypeKey" : "d568ed02-fc0c-4eba-8b3c-167526400453",
    "udi" : null,
    "key" : "e6f9be94-6ff2-46a0-ae13-22d2398acb08",
    "values" : [ {
      "editorAlias" : "masterSelectors",
      "culture" : null,
      "segment" : null,
      "alias" : "country",
      "value" : "[{\"id\":\"98\",\"name\":\"Spain\"}]"
    } ]
  }, {
    "contentTypeKey" : "d568ed02-fc0c-4eba-8b3c-167526400453",
    "udi" : null,
    "key" : "50cc86ed-bf99-45da-b290-243f5aa7ce9d",
    "values" : [ {
      "editorAlias" : "masterSelectors",
      "culture" : null,
      "segment" : null,
      "alias" : "country",
      "value" : "[{\"id\":\"129\",\"name\":\"France\"}]"
    } ]
  } ],
  "settingsData" : [ ],
}

Where will show the value Spain

However, in U15,
I have tried
{= country[0].name}:cross_mark:

{umbValue: country | first} :cross_mark:

{umbValue: country[0].name} :cross_mark:

{umbValue: country} :cross_mark:

{umbLink: country.name}:cross_mark:

Also for label display, how can do conditional display or iif inside ?
like before
{{ (default == true) ? ‘no value’ : ‘have value’}}

Appreciate for your help.