For every trigger, action, or search, you need to select a Base & Table and optional View. This is done with 3 simple dropdowns, starting first with the Base. This will list all Bases that the API used in authentication has access to.
Once a Base is selected, then all the Tables associated with that Base will be made available in the Table dropdown.
Similarly, once a Table is selected, then all Views associated with the selected Table will be made available.
The View selection are optional. If selected, it will filter the Fields available for selection, retrieval, and updates.