[Busla]

Код:

select ID.user, FIO.user, Title.c1, Title.c2, Name.location, c1.Status from user
  inner join (select distinct IDUser, IDConference from application) as app on ID.user=IDUser.app
  inner join conference as c1 on IDConference.app=ID.c1
  inner join conference as c2 on IDConference.app=ID.c2 and c1.ID!=c2.ID
  inner join location on c1.IDLocation=location.ID
  where c1.DateBegin between c2.DateBegin and c2.DateEnd;