How do you select anchor points on a brush stroke?

Hi, This may be a stupid question but i'm new to flash.

I am doing rotoscoping and draw with the brush tool on a new layer over the top of a live action video.

I would like to be able to use the subselection tool on my previously drawn brush lines and move segments of the lines rather than redrawing them for the next frame.

The problem is that with the subselect tool I can only seem to select points either on the inside or outside of the brush line, meaning I can only expand part of the line. I would like to be able to select the matching inside and outside points at the same time and move them together.

Here is an example of how I can only select inside points