Migx внутри Migx через Fenom

{set $rows = json_decode($_modx->resource.main_tv, true)}
{foreach $rows as $row}
    {$row.item}
    {$row.items} // Это поле с вложенными элементами
{/foreach}

{set $rows = json_decode($_modx->resource.main_tv, true)}
{foreach $rows as $row}
    {$row.item}
    {set $rows = json_decode($row.items,true)}
    {foreach $rows as $row}
        <div>{$row.span}: <strong>{$row.strong}</strong></div>
    {/foreach}
{/foreach}

{set $rows = $_modx->resource.main_tv | fromJSON}
{foreach $rows as $row}
    {$row.item}
    {set $childRows = $row.items | fromJSON}
    {foreach $childRows as $chRow}
        <div>{$chRow.span}: <strong>{$chRow.strong}</strong></div>
    {/foreach}
{/foreach}