As you know, at a time you can open only one test and work with it.
Sometimes you may wish to see scipt of other tests along with current test to compare/modify them.
For this,in the file sytem, manually navigate to test folder.
Drag the "script.mts" present inside the action folder to QTP tool.
Now in QTP tool, you will see a new window to view/edit&save that script.
You can drag as many script files as you wish
Note:You can not run tests this way!you can only change the content of script.