Albion signed the defender from Fiorentina for a fee worth up to £17 million in the summer of 2023, and since then, he has made 50 appearances for the club.
But competition for places and a hamstring injury, which kept him out for much of last season, led to the Brazilian considering a summer exit from the Amex.
Now, after heading to the Hammers on a season-long loan, the 27-year-old has talked up his time at the Sussex outfit and the role former Albion head coach Graham Potter had in the move.
He told West Ham's website: "I had the chance to go to Brighton and to fulfil a dream as well, which was to play in the UEFA Europa League.
"I’m very grateful for everything I went through at Brighton during those years, for everything I learnt there, and to all the staff who helped me grow and evolve as a player, too.
"First of all, he [Potter] gave me the opportunity to come to a big Club and told me he would use me, that he would give me the chance I really need.
"That was very convincing. He’s also a very well-known coach. I think it’s important for me, especially at this point in my career, to work with a manager who has so much knowledge of the Premier League."
The former Fiorentina man, who saw a move to Crystal Palace fall through on deadline day, could make his West Ham debut when Potter's team take on local rivals Tottenham in the Premier League on September 13.
While he will be ineligible to play, due to the rules of his loan, the Hammers travel to Albion on December 6 before the return fixture takes place less than four weeks later on December 30.
He added, "West Ham is a big club in England. I already knew about the club, I had already played against them before, and from the moment the speculation arose, I got really excited and delighted to have the opportunity with West Ham."