It varies widely. The Daniel / Revelation stuff is often just the recruitment seminars. But will show up as a study topic from time to time.
Sabbath School ( Sunday School ) they have a lesson guide they study through which is generally based on either a topic or a book of scripture. This is issued nationally at a minimum but its not mandatory to use. As the “small group” wave sweeps the nation they are tending to use other sources for this.
A midweek is more the spot you might see the study of a particularly EGW book or home study groups. More home study. I’ve seen them study Messages to Young People, Education, Ministry of Healing, Desire of Ages and the like.