with rs as (
  select 0 as id, '' as g, sysdate as d, 0 as v, '' as cond from dual where 0=1
  union all select 1, 'a', date'2021-01-01', 10, 'abc' from dual
  union all select 2, 'b', date'2021-01-01', 20, 'def' from dual
  union all select 3, 'b', date'2021-01-01', 15, 'abc' from dual
  union all select 4, 'c', date'2021-01-01', 30, 'qwe' from dual
  union all select 5, 'c', date'2021-01-01', 25, 'asd' from dual
  union all select 6, 'd', date'2021-01-01', 20, 'abc' from dual
  union all select 7, 'd', date'2021-01-01', 10, 'asd' from dual
  union all select 8, 'd', date'2021-01-01', 35, 'zxc' from dual
)
select rs.*
, case when cond = 'abc' then 1 end as is_root
, max(id) keep (dense_rank first order by case when cond = 'abc' then 1 end) over (partition by g) as root_id
, max(v) keep (dense_rank first order by case when cond = 'abc' then 1 end) over (partition by g) as root_v
, max(case when cond = 'abc' then id end) keep (dense_rank first order by case when cond = 'abc' then 1 end) over (partition by g) as root_id2
, max(case when cond = 'abc' then v end) keep (dense_rank first order by case when cond = 'abc' then 1 end) over (partition by g) as root_v2
from rs
order by 1