فَإِنْ كَانَ مُقِيمًا: صَلَّى بِالطَّائِفَةِ الْأُولَى رَكْعَتَيْنِ، وَبِالثَّانِيَةِ رَكْعَتَيْنِ
Translation: If the imam is resident, he prays two rakahs with the first group and two with the second.
This describes a four-rakah obligatory prayer. The imam prays two rakahs with the first group and two with the second, completing four total.
The first group completes its remaining two without recitation as lahiq; the second group completes its remaining two with recitation as masbuq.