Hi @AKG123,
Do you want to filter the order dropdown based on the case selected from the case dropdown?
Could you please tell me that if there is a primary key between case list and order number list?
Tell me that how you set the Items property of the Dropdown1?
For example, there is an caseID column in both case list and order number list, then we could retrieve order number based on the caseID from the case list.
You should set the items property of the Dropdown4 as below:
Filter('Work Orders',caseID=LookUp(CaseList,CaseNumber=Dropdown1.Selected.CaseNumber).caseID).WorkNumber)