Whilst I appreciate you may be seeking a direct answer to your question (which others appear to have helped you with) I would encourage you to take a step back.
You are currently going direct to the phase filters in properties and asking which one do I use? but I would encourage you to go to the phasing dialog under the manage ribbon and select the phase filters tab. here you will see a table of these choices that you have been discussing.
Most importantly though, it is here you can learn and understand why filters show (or not) various objects.
So to answer your question another way, in this dialog look for the phase filter that has 'by category' under the 'new' column and 'do not display' in the remaining columns. In my template i created and named this "Current Phase Only".
So now, when using 'Exisiting Phase' set this 'Current Phase Only' as your filter.
Another example is wanting to see your final completed project without the existing being grey.
Therefore you need a filter that has 'by category' set for both the 'new' column and the 'existing' column. (As we dont want anything overridden with grey) 'Do not display' assigned to the remaining columns. In my template this is named 'Completed Project'.
Understanding this principle will enable you to tweak, rename, delete and create new filters to suit your needs and thereby hopefully make you feel as though you are in control, otherwise its just trial and error.
Hope it helps.