From what I can see the problem is splitting the 'members' up.
If you just want a query for all local users - you choose
Local Users and Groups > Local User Accounts > Name - Exists.
Then add the Local Users and Groups > Local User Accounts > Name column to the Query.
if you want the members its
Local Users and Groups > Local Groups > Members -
but i tried putting Not Like - Domain\ -
then adding the Local Users and Groups > Local Groups > Members - column to the Query
This however as the members are returned in a string it wont show you any machines with any Domain accounts in which is not what you want.
You need to do a SQL query to look at the string then split it by the delimiters ; and strip out all Domain\ before returning the results..
I am trying something now.... if there are any advanced DBAs who can help great.