Azure data factory get object properties from array

I have a Get Metadata activity which get all child items under a blob container. There are both files and folders but i just need files. So in a filter activity which filter for only items of type = file. This is what I got from the filter activity:

    Output
    {
        "ItemsCount": 4,
        "FilteredItemsCount": 3,
        "Value": [
            {
                "name": "BRAND MAPPING.csv",
                "type": "File"
            },
            {
                "name": "ChinaBIHRA.csv",
                "type": "File"
            },
            {
                "name": "ChinaBIHRA.csv_20201021121500",
                "type": "File"
            }
        ]
    }

So there is an array of 3 objects being returned. Each object has a name and type properties. I want just the names to be fed to a store procedure activity as a parameter. I have used this expression to try to get a comma separated list as the parameter.

    @join(activity('Filter1').output.Value.name, ',')

and got this error:

            The expression 'join(activity('Filter1').output.Value.name, ',')' cannot be evaluated because property 'name' cannot be selected. Array elements can only be selected using an integer index.

So how can I achieve this?

You can create For Each activity after Filter activity. Within For Each activity, append file name.

Step:

1.create two variable.

2.Setting of For Each activity

3.Setting of Append Variable activity within For Each activity

4.Setting of Set variable