This practice, brought in by the Spaniards, who colonized the Philippines. Goes back to the time of the early church where Christians would visit the seven great basilicas (The Saint John Lateran, St. Peter, Saint Mary Major, Saint Paul Outside the Walls, Saint Lawrence Outside the Walls, Holy Cross in Jerusalem and Saint Sebastian Outside the Walls) in Rome for the worship of the Blessed Sacrament during Holy Thursday.
For devoted Filipinos, it is not just the Blessed Sacrament but a reflection of the Fourteen Station of the Cross. And, for the churches, they really give time and effort to embellish their church for the visitors to feel the solemn and and eagerly contemplate on what Christ been sacrificed.