This happens when you pick users and groups.... you can only pick users in sharepoint person or group field when setting up that field. 

@igorsp , I would say it is because the column is configured in SP to allow People and Groups.
If it is configured with People Only and Allow multiple No, you will see the People Field broken down like this:

 

What about when you need to select an office 365 group, what do you do then?

@Deon @brandiwoodson 

@jr123456 ,

have you looked at these actions?

@Deon Can I input the ID of a 365 Group outputted from the Query a List action or how do you get a particular group?

@jr123456 , it seems there are now so many different types of Groups in Azure and SharePoint.

The ID returned from the List people and group column is integer, but Microsoft 365 Groups has a GUID as an ID. It seems that when you USE a Microsoft 365 Group in the people and group column, SharePoint will create a dummy group with an integer id under the site groups, but you can’t get to that via the REST API, it doesn’t even come back when you ask for all Site Groups and when you make a REST API call to get members using the integer ID, you get:

{
    "error": {
        "code": "-2146232832, Microsoft.SharePoint.SPException",
        "message": {
            "lang": "en-US",
            "value": "Group cannot be found."
        }
    }
}

May I ask if the groups you are interested in is:

1. Under Microsoft 365 Admin Center
   • Teams & Microsoft 365 Groups?
   • Distribution List?
   • Security Group?
2. Under Site Permissions - Site Group (i.e. a SharePoint Group)

The groups you see in 1. above are also in AAD so that is another option.