Hi there @Madison_Silvert ! Welcome to Coda 
and to the Community 
.
I’ve copied your doc and modified it a little bit to create Lookups 
(See below).
(Which is easy to do as you just need to convert your select list into tables 
)
So, you now have a table called Property and another one called Unit/Suite.
In Unit/Suite, I added a lookup field to be able to select the Property in which each Unit/Suite is.
Back to the Log table, you can now filter your Unit/Suite lookup field by indicating in the Items settings to get only the Unit/Suite (from the Unit/Suite table) for the Property selected in the Property field .
(You could use a formula there, but Coda, will suggest this filter all by itself )
