I know that this question has been asked several times, but I can't figure out how to solve this. I have a table that has data with a date field and the field can be empty or not. I would like to have the date field=null selection applied when I load the app and give the user the possibility to remove this filter. In oder to do this I am using a listbox with a flag that applies the filter when is pressed and to keep it selected opening the app I use an extension that applies a bookmark when the app is loaded. The problem is that if I do other selections and I go to other sheets of the app and then I come back to the first one that has the bookmark applied, this deletes all other selections.