Can i SELECT two user names by id in another table with join?
For MySQL, see here: https://www.db-fiddle.com/f/sjtJBAccd4gvZYZChbuWmx/1

create table sb_bans (
bid     int,
bannerid int,
unbannerid int
);

create table sb_admins (
aid int,
name varchar(10)
);

insert into sb_bans values (1,26,26);
insert into sb_bans values (2,27,13);
insert into sb_bans values (3,10,13);
insert into sb_bans values (4,11,27);
insert into sb_bans values (5,13,10);

insert into sb_admins values (10, 'Tomi');
insert into sb_admins values (11, 'Dominik');
insert into sb_admins values (13, 'Michal');
insert into sb_admins values (26, 'Kristian');
insert into sb_admins values (27, 'Daniel');

select b.bid,
       s.name as banner_id,
       s1.name as unbannerid
  from sb_bans b
  join sb_admins s
    on b.bannerid = s.aid
  join sb_admins s1
    on b.unbannerid = s1.aid