question

First, the Matchmaking Rule cannot be used to prevent the player from using the system based on their statistics (level), instead, you should prevent them from creating the matchmaking ticket in the first place. Since you think the client can still bypass the “if statement”, therefore you can consider using server-side logic such as CloudScript to first verify the player level, and if it passes, create the ticket using CreateServerMatchmakingTicket and return necessary info back to the clients accordingly.

The attribute path means the path to a player’s attribute, depending on the attribute source. There are two attribute sources: 1) the create ticket request (for rules configured with the attribute type “User” ) ; 2) the player’s entity (for rules with attribute type “Player Entity” ). Please go through this doc to learn more about the attribute path and how to use them: Specifying attributes with your tickets - PlayFab | Microsoft Docs

Regarding the region selection rule, you got most of the parts correct. The attribute path you should put in for it is simply “Latencies”:

And, please note that region selection rule requires a more complex attribute format used in the CreateMatchmakingTicket request, here is a sample:

POST https://{ {TitleId}}.playfabapi.com/Match/CreateMatchmakingTicket

POST https://{
                {TitleId}}.playfabapi.com/Match/CreateMatchmakingTicket
{
    "Creator": {
        "Entity": {
            "Id": "A8140AB9109712B",
            "Type": "title_player_account",
            "TypeString": "title_player_account"
        },
        "Attributes": {
            "DataObject": {
                "mu": 16.0,
                "sigma": 1.8,
                "Latencies": [
                    {
                        "region": "EastUs",
                        "latency": 150
                    },
                    {
                        "region": "WestUs",
                        "latency": 400
                    }
                ]
            }
        }
    },
    "MembersToMatchWith": [],
    "GiveUpAfterSeconds": 2,
    "QueueName": "ServerEnabledQueue"
}

You can find more details in this section: https://docs.microsoft.com/en-us/gaming/playfab/features/multiplayer/matchmaking/ticket-attributes#special-formats