Hmm, I don’t think it’s possible, at least I don’t know any solution. The NERDTree window is positioned differently, even if you open another window and switch the tree, this will affect one.
, , , . , , NERDTree:
'NERDTreeWinPos'
Values: "left" or "right"
Default: "left".
This option is used to determine where NERD tree window is placed on the
screen.
This option makes it possible to use two different explorer plugins
simultaneously. For example, you could have the taglist plugin on the left of
the window and the NERD tree on the right.