e.g. Create a security group called LocalAdmins-PC1 for PC called PC 1 apply this policy preference and those users that are members of LocalAdmins-PC1 will have local admin rights
You create security groups with the Computer name in them . The policy then uses the environment Variable %Computername% to apply the security group just for that computer.
e.g. create security groups
LocalAdmins-PC1
LocalAdmins-PC2
LocalAdmins-PC3
LocalAdmins-PC4