How to Create a Drop-Down List Based on Column in Spreadsheet

[ConnieMaldonado]

Sorry for the long post. I am a newbie and am in prototype mode to test whether AppSheet will work for what I’m doing. I chose AppSheet for speed in getting the app up and out there.
I am working on a field service app to track work completion for technicians in the field. We are installing beacons, aggregators, and gateways at large hotel properties to provide an alert system to staff in case of an active shooter or other emergency. Have over 4,400 properties to complete.

The initial layout of the hotel will be provided in a spreadsheet (one spreadsheet per property). I have fields for building (in case property has multiple buildings), floor, and area (e.g., guest room, bathroom, office, etc.) See Sample Data Image.

I’m using a table view so the tech can easily select the correct Building and Floor (Table View 1 image), and I would like to have a drop-down for the area selection (Table View 2 image). Where can I find information on how to set up a drop-down list based on a column in the spreadsheet?

Once the tech selects the area, they will then indicate the number of beacons, aggregators, and gateways installed (Table View 3 image).