DHCPS - single mac whitelist, multiple subnets

Question

I am trying to reduce the size of my broadcast domain and, in order to do this, I need to permit hosts from being able to move from one subnet to another at will.

We use a mac whitelist for our dhcp services and the issue I have is that I can only declare the whitelist in one subnet, otherwise I get a conflict error and the dhcpd service won't start.

Is it possible to have a single declaration, or multiple references to the same file, where I can have a single whitelist across multiple subnets?

# VLAN 157 - USERS 157

subnet 10.194.142.128 netmask 255.255.255.128 {
    option domain-name-servers 10.194.0.2 , 10.194.0.3;
    pool {
        range 10.194.142.138 10.194.142.250;
        include "/etc/dhcp/Client_Groups/Clients.conf";
    }
    option routers 10.194.142.129;
    deny unknown-clients;
    allow client-updates;
    ddns-updates on;
}