Why not just check in your code if(items == 10 && players == 3) and then set a boolean which you check in the itemDef.
Some like:
PHP Code:
if(items == 10 && players == 3)
{
player setClientCvar("show_item10", 1)
}
else
{
player setClientCvar("show_item10", 0)
}
PHP Code:
dvartest "show_item10"
showDvar{ "1" } //not sure if with or without quotation marks
I know you want it to be easier, but I have never seen a double dvar check in menus. And this is the easiest way that by now has popped into my mind.