gitg does not aim to be an advanced
tool that allows access to every
feature of Git through a graphical
interface. However, it will try to
incorporate common actions that might
require multiple actions on the
command line (like staging, unstaging,
reverting, and committing)
Your best bet is the command line git log <file> or gitk <file>
Short answer, no it can't do that (in v0.0.6).
gitg claims:
Your best bet is the command line
git log <file>
orgitk <file>