Pages remembers its last document saved folder location. That will be the default on subsequent saves, unless you catch it and choose another destination. The following was tested with Pages v8.2.1 on Mojave (10.14.6).
Without opening Pages, or hunting for a last saved file location, AppleScript can tell you where that last saved folder location resides, by asking the Pages preference list (.plist):
use framework "Foundation"
use AppleScript version "2.4" -- macOS Yosemite 10.10 or later
use scripting additions
property NSString : a reference to current application's NSString
-- get the last directory location that Pages saved too.
set lastFolder to (do shell script "defaults read com.apple.iWork.Pages NSNavLastRootDirectory")
if not lastFolder is "" then
set relpath to NSString's stringWithString:lastFolder
display dialog (relpath's stringByStandardizingPath) as text
else
display dialog "Pages last saved folder not found"
end if
return
Pages always stores the last saved location as a tilde (~) path if located in your home directory, or icloud destination. I convert that path to an explicit, full path in the above code. Anything stored on iCloud will have your local Mobile Documents folder in the output path.
From Dock : Launchpad : Other, click on Script Editor. Copy/paste the above AppleScript code into it, and click the hammer (compile) icon. The text will change colors which indicates a good compile. Then just click the run button. You can save this AppleScript as a script (scpt), script bundle (scptd), or application (.app) on your Desktop, where you can run it with a double-click.
