Can we know whether any distant galaxy is moving away in same direction or in opposite direction w.r.t. our galaxy? The Hubble law states that the recessional velocity of a galaxy is proportional to its distance from us.
It takes redshift and angular sizes (for distance) of the galaxy to determine velocity, and thus rate of expantion.
But I guess the factor of direction in which the galaxy is moving may substantially affect the 'expantion rate' calculations. i.e. If the galaxy A is moving in same direction as ours, will have less relative speed and the galaxy B moving in opposite direction will have more relative speed. The actual local speed may be the same.
I wonder whether this fact can be considered when we determine the expansion rate?
Yes, it can. For instance the Andromeda Galaxy is moving towards us, due to local gravitational attraction but that does not affect the validity of the theory of the expansion of spacetime because one result based on local factors is perfectly compatible with a cosmological theory which, by definition, includes every galaxy.