Or search: richness, grandness, stateliness, magnificence
2 Syllables: SU
families, family's
3 Syllables: SUU
agonies, batteries, fallacies, fantasies, flatteries, galleries, magazines, Majesties, majesty, maladies, salaries, strategies, tapestries, tragedies, travesty, vanities
4 Syllables: USUU
academies, analogies, calamities, capacities, catastrophe, disastrously, formalities, realities
5 Syllables: UUSUU
abnormalities, generalities, technicalities

Found 29 words across 4 groupings. Skipped 1 excess word of a similar stem.