  Direct comparison between stellar and solar magnetic maps are hampered by
their dramatic differences in resolution. Here, we present a method to filter
out the small-scale component of vector fields, in such a way that comparison
between solar and stellar (large-scale) magnetic field vector maps can be
directly made. Our approach extends the technique widely used to decompose the
radial component of the solar magnetic field to the azimuthal and meridional
components as well. For that, we self-consistently decompose the
three-components of the vector field using spherical harmonics of different $l$
degrees. By retaining the low $l$ degrees in the decomposition, we are able to
calculate the large-scale magnetic field vector. Using a synoptic map of the
solar vector field at Carrington Rotation CR2109, we derive the solar magnetic
field vector at a similar resolution level as that from stellar magnetic
images. We demonstrate that the large-scale field of the Sun is not purely
radial, as often assumed -- at CR2109, $83\%$ of the magnetic energy is in the
radial component, while $10\%$ is in the azimuthal and $7\%$ is in the
meridional components. By separating the vector field into poloidal and
toroidal components, we show that the solar magnetic energy at CR2109 is mainly
($>90\%$) poloidal. Our description is entirely consistent with the description
adopted in several stellar studies. Our formalism can also be used to confront
synoptic maps synthesised in numerical simulations of dynamo and magnetic flux
transport studies to those derived from stellar observations.
