If I am at home and made a Hadama on a snack and finished eating it then decided I want to eat another snack that was not in front of me when I made the bracha, do I need to make another Hadama? Will the halacha be different if I was a guest somewhere?
If you had in mind when you said the bracha that you only want to eat this food and nothing else, then you would make another bracha. However, if you didn’t specifically think that you are specifically only eating this, you do not need to make another bracha, The reason is because when a person is eating at home, he will eat one thing n then eat something else. When he finishes the first item, he isn’t really separating himself from eating. Therefore, the next snack is included in the first bracha.
M:B 174-18, Sharei Habracha 13-31.