Complex sentence: In the US, the song debuted at number 4 on the Bubbling Under Hot 100 Singles chart, a 25 track extension to the Hot 100, later debuting on the "Billboard" Hot 100 at number 69.
Split into simpler sentences: In the US, the song debuted at number 4 on the Bubbling Under Hot 100 Singles chart. The following week, it debuted on the "Billboard" Hot 100 at number 69.