Very cool, and a nice introduction to dynamic parameters in Alteryx:
For some reason it won't allow me to upload .yxwz files, so I've uploaded as a standard workflow.
OK, first of all I was trying to populate the drop down using the values from the input so I take all of them in consideration. I was not able to make it work even it says on the help that should be possible using a connected tool.
Long story short I just populate the drop down using a list of fixed values.
PD: For some reason I was unable to load my yxmz file.