I don't think you can. But i never tried to select multiple time markers, so I could be wrong.
If your timing is out by the about the same through that whole section, shift your first cue forwards until its in time, then put all the following ones the same distance in front of the markers. Remember to zoom in far enough to be accurate. You can drag to highlight all the cues and move them as a block also.
It's a matter of move it, play it - move it again most of the time. I just use markers as a rough guide then drill in to the exact time from there.
At least thats what I have always done with showtime, beyond is no different there.
[edit] if you just want to move the markers, you can move them one at a time for sure by placing the cursor in the correct place and pressing CTRL-m and that moves the closest marker to the cursor to the cursor position [edit]
