The way to add and remove people to lists is so convoluted and counter-intuitive.
First select a filter type, then, for example, a Community Builder field. Filter by ID? This means you have to know it in advance. So you try username = whatever. (is it case sensitive? did you spell it correctly?)
Then select an action: Remove an email from the queue? Which queue? I thought I was in lists? OK try AcyMailing List. then Remove users from listname. Press 'Process'. If you did something wrong all you get is "0 users removed from the list "2"" List 2? That's not what I called it.
Have they heard of lists and checkboxes?
Sorry to cumbersome for me.
The filters/actions are there to execute mass actions on your subscribers...
That's obviously not the standard way if you want to subscribe one user to a list!
-> You can edit your user and select his subscription (this is where you will see the checkboxes)
-> You can select users from the Users listing and click on the button to subscribe them all to a list