  There should be about 10,000 stellar hierarchical systems within 100 pc with
primary stars more massive than 0.5 Msun, and a similar amount of less massive
hierarchies. A list of 8000 candidate multiples is derived from wide binaries
found in the Gaia Catalog of Nearby Stars where one or both components have
excessive astrometric noise or other indicators of inner subsystems. A subset
of 1243 southern candidates were observed with high angular resolution at the
4.1 m telescope, and 503 new pairs with separations from 0.03" to 1" were
resolved. These data allow estimation of the inner mass ratios and periods and
help to quantify the ability of Gaia to detect close pairs. Another 621
hierarchies with known inner periods come from the Gaia catalog of astrometric
and spectroscopic orbits. These two non-overlapping groups, combined with
existing ground-based data, bring the total number of known nearby hierarchies
to 2754, reaching a completeness of ~22% for stars above 0.5 Msun.
Distributions of their periods and mass ratios are briefly discussed, and the
prospects of further observations are outlined.
