Qualification is based on last season Weeksy, not previous glories.
Qualification yes, overall seeding, no. That’s based upon performances of the ‘league’ in the major competitions on previous, previous seasons.
https://en.wikipedia.org/wiki/UEFA_coefficient
The order of the four pots – each comprising of eight teams – is determined by Uefa’s club coefficient ranking, which calculates a mark for each club taking into account their record in European competition over the past five seasons.
Victory for Benfica in their play-off tie with PAOK Salonika – confirmed by last night’s 4-1 second leg rout in Greece – secured the Portuguese side a place in Pot 2 and ended Liverpool’s hopes of moving up into the second tier of seeds. Though Benfica lost all six of their Champions League fixtures last term, they have been an ever-present in Europe’s top tier for the last five campaigns and reached the quarter-finals in 2015/16 as well as the Round of 16 the following season.
Read more: Liverpool’s Champions League group and fixtures – in full
Liverpool, meanwhile, have only qualified for the Champions League in two of the last five seasons. They may have reached the final last time out, but Benfica have pipped them to Pot 2 on the basis of long-term consistency.