MySQL 8.0

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create table my_table (ID int,  Name varchar(10),  RelatedTo int, CreatedAt date, Revision int)
insert into my_table values (1, 'A', null, '2019-11-01', 0)
insert into my_table values (2, 'B', null, '2019-11-01', 0)
insert into my_table values (3, null, 2, '2019-11-04', 1)
select a.RelatedTo,max(a.name),  max(a.m) 
from (select RelatedTo, name, max(CreatedAt) m from my_table 
where RelatedTo is not null
group by RelatedTo, name
union all
select id, name, max(CreatedAt) m from my_table 
where RelatedTo is null
group by ID, name ) a
group by a.RelatedTo
order by a.RelatedTo


RelatedTo
max(a.name)
max(a.m)


1
A
2019-11-01

2
B
2019-11-04