ColA | ColB |
     500001| Network1|      
     500001| Network2|
     500002| Network2|
     500003| Network1|      
     500003| Network3|</

##</code><code>##

$var1 => {500001 => Network1 , Netowrk2}
{500002 => Netowrk2}

{500003 => Netowrk1 , Netowrk3}

##</code><code>##

{500001 =>  Netowrk2}
{500002 => Netowrk2}

{500003 => Netowrk3}