I need help creating a professional services application

Hello, I am new to Bubble and I am creating a professional services application and I need to have a category and within this a subcategory and this in turn a subcategory but on the main screen only the categories should be shown and when clicking on them, show the corresponding subcategories or if the user uses a search box to go directly to the item they are looking for, I hope to express my idea well since I don’t speak much English, I appreciate your help in advance