example

local GroupId = 2886609;

function checkOkToClick(name)
    if game.Players[name]:IsInGroup(GroupId) then
        return true;
    end
    return false;
end

script.Parent.MouseClick:connect(function(PlrWhoClicked)
    local human = PlrWhoClicked.Character.Humanoid.Parent:FindFirstChild("Humanoid");
    if (checkOkToClick(human.Parent.Name)) then
        local Door1 = script.Parent.Parent.Parent.LGate:GetChildren();
        local Door2 = script.Parent.Parent.Parent.RGate:GetChildren();
        for i,v in pairs(Door1) do
            if v:IsA("BasePart") then
                v.Transparency = 1;
                v.CanCollide = false;
                wait(3);
                v.Transparency = 0;
                v.CanCollide = true;
            end
        end
        for i,v in pairs(Door2) do
            if v:IsA("BasePart") then
                v.Transparency = 1;
                v.CanCollide = false;
                wait(3);
                v.Transparency = 0;
                v.CanCollide = true;
            end
        end
        local Door1OPEN = script.Parent.Parent.Parent.RGateOpen:GetChildren();
        local Door2OPEN = script.Parent.Parent.Parent.LGateOpen:GetChildren();
        for i,v in pairs(Door1OPEN) do
            if v:IsA("BasePart") then
                v.Transparency = 1;
                v.CanCollide = false;
                wait(3);
                v.Transparency = 0;
                v.CanCollide = true;
            end
        end
        for i,v in pairs(Door2OPEN) do
            if v:IsA("BasePart") then
                v.Transparency = 1;
                v.CanCollide = false;
                wait(3);
                v.Transparency = 0;
                v.CanCollide = true;
            end
        end
    end
end)