Hi Cara, sorry for the slow response on this. One strategy for this would be to do something like in this example where I have set the year field to be a range between two values. If your goal is to show all years by default you could have the filter show dates between the first and last fiscal year. If your goal is to show one year, you could set the start and end year to be the same value. Either way you should provide some hint text to assist users in exploring the data. In this case, I created the Year filter first and then type (in this case Fujita Scale) second. This text is all defined within the map viewer when you are creating the filter.
You can also provide more custom text within the app above the filter settings. in this example built using the filter above, you can see the default text "Filter the layer by specifying values." In this example 2, I've authored some additional helper text add added it via the Filter Text dialog within the app configuration panel.
let me know if you have any questions.
Ian