The general belief is that this is two different groups. The crowd greeting Jesus on Palm Sunday is explained in John's Gospel chapter 12
"When the great crowd of the Jews learned that he was there, they came, not only on account of Jesus but also to see Lazaros, whom he had raised from the dead. So the chief priests planned to put Lazaros also to death, because on account of him many of the Jews were going away and believing in Jesus. The next day a great crowd who had come to the feast heard that Jesus was coming to Jerusalem." So these are followers or at least curious about Jesus as a miracle worker.
The crowd that was assembled on the morning of Friday was assembled during the nighttime / dawn trials of Jesus between Pilate and the Sanhedrin. Most likely this was a group of Pharisees, Saducees, and possibly merchants and temple officials. It is doubtful that most of the ordinary citizens or Jesus's supporters were even aware of the arrest of Jesus.