Are you talking about Yibir? Jewish/Hebrew notions is is something made up by them albeit ''recently'' around the 1970s to dignify their own status. It is not something that other Somalis claimed or believe about them:
As a anthropologist studying them points this out:
According to Virginia Luling, the 'Hebrew' idea is not an anti-Semitic invention by others, but was and is maintained by the Yibr themselves, who have found in this a way of dignifying their outcast status
When in reality they are the most looked down upon out of all the Sab groups because of their Pagan affilitations , thats what Somali tradition of Bucur Bayr shows. Yibir were most likely priest group that were previously pillars of the old religous cult prior to Islam
Which is strenghten by another thing observed in Rendille who are closely related group who broke off from Tunni/Garre Somalis have a Yibir group among them:
Viriginia Luling goes on to explain:
“An important ritual grouping among the Rendille is the Ibire (sg. Ibir) - evidently the same word as the Somali Yibir. The Ibire are men from certain lineages who enjoy high religious statues – in fact the Rendille are divided into Ibire and Wakhkamure, who are the rest of the male population, in a way reminiscent of the traditional Somali distinction between Wadaado and Waranleh. The Ibire however are chiefly respected and feared for the power of their curse. Since their position is central in Rendille society, this is always exercised deviants, to maintain justice and the Social order. And yet these pillars of society share a name with the despised anti-social vagabonds among the Somali. But the Somali Yibir also have extraordinary powers attributed to them, and are feared for the power of the curse.”22
I would also argue that it's most likely the same for Beta Isreal among Habeshas from the evidence i've seen in both texts and culture. They were Pagan Agaw that end up linking themselves to Hebrew/Jewishness link to dignify their status with a more abrahamic faith.