thanks for the suggestions @MT0 and @samhita both are very good although they didn't work in my case as expected, I suspect due to have multiple tables connected to retrieve the data.

In the end what worked was using a simple not in which filtered out all items that have condition B and only selected what's left, for example:

Select
column1
column2
column3

from 
table.a,
table.b,
table.c
and
a.field1 not in 
(select 
a.field1

from
from 
table.a,
table.b,
table.c
where
a.field1.=b.field2
and c.field1=b.field1
and
condition like 'B'
)