Hi @nicklim
As @Nived_Nambiar mentioned, the JSON that gets created when email addresses are added to multiple Claims lines manually looks as follows:
[
{
"Claims": "username@company.com"
},
{
"Claims": "username2@company.com"
}
]
The workaround is to use the following formulas:
first(split(triggerOutputs()?['body/ccRecipients'], ';'))
first(skip(split(triggerOutputs()?['body/ccRecipients'], ';'),1))
first(skip(split(triggerOutputs()?['body/ccRecipients'], ';'),2))
However, you need to specify EXACTLY a set number of items to select in the SharePoint list's multiple value column.
I have made a simple test for your reference.
1. Here is the flow:

2. Result of receiving two cc emails:

In SharePoint list, CC is the person column which allows multiply collections:

After the flow triggered, a new item was created in SP list with two cc emails uploaded:

Here is the doc for your reference:
Add multiple users to SharePoint multiple user or group column · Community (powerautomate.com)
Hope it helps!
Best regards,
Sylvia