The Merge folder comparison window enables you to review and merge the changes within different versions of a text file by launching text, image or binary comparisons for each row of files that interests you.
To view the changes to a file, first select the file by clicking on it in the results list. Next, click the Launch Comparisons 
toolbar button. You can also select the Actions▸Launch Comparisons For Selected Rows menu item. A file comparison window will open and you can review and reconcile the changes between the versions of the file.
Launching multiple file comparisons
You can open file comparison windows for more than one file at a time by selecting multiple files in the folder comparison results list before choosing the Launch Comparisons button. You can also select the Actions▸Launch Comparisons For Selected Rows menu item. Hold down Cmd or Shift when clicking on files in the folder comparison windows to select multiple files.
You can also click the Select Rows 
toolbar button and select Select Changed to select all the changed files before clicking on the Launch Comparisons toolbar button.
Limiting the number of opened file comparisons
To avoid an overwhelming number of windows being opened at a time, there is a configurable limit on the number of file comparison windows that the folder comparison window will open. This limit can be adjusted using the controls on the Launch page in the Settings window.
A typical method of working is as follows:
- Click the Select Rows toolbar button and select Select Changed to select all the files that have changed between the first and second folder hierarchies.
- Click the Launch Comparisons toolbar button to open a file comparison window for each of the selected files. A file is deselected when a file comparison window is opened for it.
- Review and/or edit the content of the file comparison windows that were opened. Close each file comparison window when you have finished with it.
- Return to the folder comparison window when you have closed all the file comparison windows.
- Click the Launch Comparisons toolbar button again. If there are any remaining selected files in the list, another batch of file comparison windows will be opened.
Repeat the last three steps until there are no more selected files.
Updating the folder comparison after editing files
To update the folder comparison after making changes to a file, select the file and click the Retest Selected 
toolbar button. You can also select the Actions▸Retest Selected menu item, or press Shift+Cmd+R.