  We investigate the relation between the spatiotemporal evolution of the
dimming region and the dominant direction of the filament eruption and CME
propagation for the 28 October 2021 X1.0 flare/CME event observed from multiple
viewpoints by Solar Orbiter, STEREO-A, SDO, and SOHO. We propose a method to
estimate the dominant dimming direction by tracking its area evolution and
emphasize its accurate estimation by calculating the surface area of a sphere
for each pixel. To determine the early flux rope propagation direction, we
perform 3D reconstruction of the CME via graduated cylindrical shell modeling
(GCS) and tie-pointing of the filament. The dimming initially expands radially
and later shifts southeast. The orthogonal projections of the reconstructed
height evolution of the erupting filament onto the solar surface are located in
the sector of the dominant dimming growth, while the orthogonal projections of
the inner part of GCS reconstruction align with the total dimming area. The
filament reaches a maximum speed of $\approx$250 km/s at a height of about
$\approx$180 Mm. The direction of its motion is strongly inclined from the
radial (64$^\circ$ to the East, 32$^\circ$ to the South). The 50$^\circ$
difference in the 3D direction between the CME and the filament leg closely
corresponds to the CME half-width determined from reconstruction, suggesting a
potential relation of the reconstructed filament to the associated leg of the
CME body. Our findings highlight that the dominant propagation of the dimming
growth reflects the direction of the erupting magnetic structure (filament) low
in the solar atmosphere, though the filament evolution is not related directly
to the direction of the global CME expansion. The overall dimming morphology
closely resembles the inner part of the CME reconstruction, validating the use
of dimming observations to obtain insight into the CME direction.
