Nukhim was born in 1888, had 3 siblings born in 1890's - Bentsion, Khasya (1897-died at 9 months), Gersh (died at 13 months)
Father - Movsha-Mordukh s.o. Izrail-Leyb married at least 3 times:
2nd time after Nukhim's birth
3rd time in early 1905 to a woman with last name Idel (most likely Malka-Tsyril d.o. Yankel-Leyb)
Movsha-Mordukh's sister Tsivya married in 1890's to ?
Movsha-Mordukh's brother Khaim married in early 1904 to a woman with the last name to Kerpel (Mintsya, Rukhlya, or Sara)
There is a page of people with this last name on Yad Vashem, all mostly from, what is currently, central Belarus: https://yvng.yadvashem.org/index.html?s_id=&s_lastName=chernogubovskiy