Here's a better idea: Use Script Debugger 7 .
If you don't already have it, you can get a free 30-day trial, and then it gracefully downgrades to SD7 Lite.
See this post by @ccstone: Using SD7 to View Front Window Elements
tell application "System Events"
tell application process "Keyboard Maestro"
set oWin to front window
oWin
end tell
end tell
--- AFTER the window elements are displayed, drag the element of interest to the SD code panel
-- then usually replace the window title with "window 1"
-- This is the script you need in KM to press the "Recently Used" button.
tell application "System Events"
tell its application process "Keyboard Maestro"
-- tell its window "Keyboard Maestro Editor — @MOU Move Mouse to FrontMost Window When Window Changes"
tell window 1 -- "Keyboard Maestro Editor — @MOU Move Mouse to FrontMost Window When Window Changes"
tell its group 3
tell its button "⌘" -- you could also use button 1
action "AXPress"
end tell
end tell
end tell
end tell
end tell
