For Seudat Shlishis on Shabbos we usually have a “Seuda matakim”, A seuda of Nush.
After making a hamotzei, the only items served during the meal would be bissli, popcorn, ten-chups cornmeal snacks, rogalach.
Since the nush is the integral part of the meal and not as a dessert . Which of these items require a separate bracha from hamotzei?
The Shulchan Aruch 177- 3 discusses a similar case. A person that eats a bread meal, but he is not going to eat meat etc. and he is only going to eat fruits, (which usually would need their own bracha when eaten after a bread meal). The halacha in this case is controversial, and in order avoid an issue he should eat a little bread at the beginning of his eating the fruits. The halacha would be the same here, that you should eat a little bread together with the first popcorn, first bissli etc. and then you wouldn’t have any issue.
M:B 177-15, 16,17, Horav S. Stitzberg shlit”a author of Sharrie Habracha.