Or search: berth, billet, clergy, prelacy
2 Syllables: SU
settler
3 Syllables: SUU
creditor, editor, Eleanor, Hereford, mariner, registers, Senator, treasurer
4 Syllables: USUU
competitor, developer, inheritor, investiture

Found 13 words across 3 groupings. Skipped 7 excess words of a similar stem.