How can I filter a combo box? For example I have the this to fields of combo box

I have 2 values available for Building (Building 1, Building 2)

And I have 4 available values in Floor (Floor 1, Floor 2, Floor 3, Floor 4)

If I selected Building 1 in the first combo box which is Building the value in Floor combo box should only be Floor 1 and Floor 2. If I selected Building 2 in the Building combo box the value in Floor combo box should now only be Floor 3 and Floor 4.

Need help. Thank! 

Outsystem 11

This is an old link but the logic remains similar : https://insideoutsystems.wordpress.com/2014/08/05/conditional-drop-down-lists-in-an-outsystems-application-2/

Attached a sample app and here is sample page :  https://tusharpanpaliya.outsystemscloud.com/LinkedCombos/Home.aspx