Hey there!

You're grabbing the upper part of an A major barre chord at the fifth position there. In the first measure, with that chord shape held, you're arpeggiating the D string then G string, then high E string then B string back to the G string.

In the next measure, you're arpeggiating the D string going to the G string to the high E string, then the open B string as you reposition your fretting hand to grab the A triad (6, 5, 5 on the G, B, and E strings).

With that A triad held, the next measure you arpeggiation G string, B string, E string, B string then the open B string as you reposition to the higher inversion A triad up the neck (9, 10, 9 on the G, B, and E strings).

That final measure on the higher A triad is the exact arpeggiation as the previous bar.

Make sense? Let me know how it goes!
Mike