Watch the Son Montuno Guajeo 2-3 online guitar lesson by Jesús Hernández from Buena Vista Cuban Guitar Guidebook

Here we can see that we're talking about a two bar pattern. In the first bar, we play a quarter note followed by two eighth notes, etc. And in the second bar, we start with an eighth note rest, followed by a note. This is typical of a 2/3 tumbao or guajeo.