I think you can do this with trigger actions (you have to replace Field1 and Field2 with your field names, of course):
Open Settings->document properties->triggers
In field event trigger section, select your Field1 (Listbox1 values) and add actions for OnSelect.
Add 1 action of type selection - clear field and enter the Field2 name in to right upper field (just the field name)
Then create a second action of type selection - select in field
Field is again Field2
Search string (copy literally the exact same characters):
Hope this helps,
Thank you for answering. Unfortunately your answer is not completely functional.
Selecting Field1 from low to higher values works ok, but after selecting in Field1 a smaller value than selected before does not work. This doesn't change anything. See attached qlikview file.
Btw: Action type "Clear field" is not available, so I choose : "Clear other fields"
QvTest.qvw 132.5 K
Clear Field is a new action in QV11 (well I remember an easter egg enabling Clear Field in Qv10, but let's not build on that).
Clear Other field will not work here.
But you can use selection - select in field as first action on field value2 and with a search string that will never match.
QvTest2.qvw 132.8 K