Three different men are called Bela, and the verses keep them apart only by their families. The first is Bela the son of Beor, who “reigned in Edom” in Genesis 36, the first king named in that list. The second is a son of Benjamin, whose own sons are listed in 1 Chronicles 7 as “mighty men of valour” and from whom the Belaites took their name in Numbers 26. The third, in 1 Chronicles 5:8, is a Reubenite who lived in Aroer. Genesis 36:32 is a good starting point.
7 verses
And Bela the son of Beor reigned in Edom: and the name of his city was Dinhabah.
And Bela died, and Jobab the son of Zerah of Bozrah reigned in his stead.
The sons of Benjamin after their families: of Bela, the family of the Belaites: of Ashbel, the family of the Ashbelites: of Ahiram, the family of the Ahiramites:
And the sons of Bela were Ard and Naaman: of Ard, the family of the Ardites: and of Naaman, the family of the Naamites.
And Bela the son of Azaz, the son of Shema, the son of Joel, who dwelt in Aroer, even unto Nebo and Baalmeon:
The sons of Benjamin; Bela, and Becher, and Jediael, three.
And the sons of Bela; Ezbon, and Uzzi, and Uzziel, and Jerimoth, and Iri, five; heads of the house of their fathers, mighty men of valour; and were reckoned by their genealogies twenty and two thousand and thirty and four.
Matthew George Easton, 1897
A thing swallowed. (1.) A city on the shore of the Dead Sea, not far from Sodom, called also Zoar. It was the only one of the five cities that was spared at Lot’s intercession (Gen. 19:20,23). It is first mentioned in Gen. 14:2,8.
(2.) The eldest son of Benjamin (Num. 26:38; “Belah,” Gen. 46:21).
(3.) The son of Beor, and a king of Edom (Gen. 36:32, 33; 1 Chr. 1:43).
(4.) A son of Azaz (1 Chr. 5:8).
William Smith, 1884
(destruction).
(1.) One of the five cities of the plain which was spared at the intercession of Lot, and received the name of Zoar, (Genesis 14:2; 19:22) [ZOAR]
(2.) Son of Beor, who reigned over Edom in the city of Dinhabah, eight generations before Saul. (Genesis 36:31-33; 1 Chronicles 1:43,44)
(3.) Eldest son of Benjamin, according to (Genesis 46:21) (Authorized Version "Belah"); (Numbers 26:38,40; 1 Chronicles 7:6; 8:1) and head of the family of the Belaites.
(4.) Son of Ahaz, a Reubenite. (1 Chronicles 5:8)