я нашел уникальные id (uniqColumns). по ним пробежался.
const separationData = uniqColumns?.map(item => {
    const res = []
    const arr = dataPrepare?.filter(s => s[`${Object.keys(s).find((key) => key.startsWith("id"))}`] === item)
    res.push(arr)
    return res
  })const res: DataTypeSelect[] = [];
            const itemCheck = (item: any) => {
                if (res.indexOf(item.classifId) === -1) {
                    res.push(item.classifId);
                    return true
                }
                return false;
            }
            const data = dataSource ? dataSource?.map(item => {
                return ({    
                    key: item.classifId,
                    classifName: item.classifName,
                    classifId: item.classifId
                })
            }).filter(item => itemCheck(item)) : []export type Compare = {
    channelid: number,  
    childrenHash: Child[]
}
export type Child = {
  id: number, hash: string
}
export const comparsion = (data: Compare[]) => {
    const res = data?.map((n: { childrenHash: any[] }) => {
    const ids = Object.values(n.childrenHash.reduce((acc, m) => ((acc[m.hash] ??= []).push(m.id), acc), {})).filter((m:any) => m.length > 1);
    return {
      ...n,
      childrenHash: ids.length ? ids : null,
    };
  })
  return res
}