How do I get a list of all applications that can be executed from Ubuntu Dash Home? Is there is some xml file that stores this information?

I understand from the comments that the OP likes the output from the linked code but would like the information placed into an xml file that can be queried.

Her'es how to modify the script given at Get contents of .desktop files to process the output into an XML file.

filename="MyDesktopFiles.xml"
rm $filename
touch $filename

echo '<?xml version="1.0"?>' >> $filename
echo '<items>' >> $filename

for files in /usr/share/applications/*.desktop; 
do 
  echo '<item>' >> $filename
  echo '   <name>'$(grep -e "^Name=" $files | sed 's/Name=//g')'</name>' >> $filename   
  echo '   <command>'$(grep -e "^Exec=" $files | sed 's/Exec=//g')'</command>' >> $filename
  echo '</item>' >> $filename
done

echo '</items>' >> $filename
echo '</xml>' >> $filename