Altova DiffDog 2023 Professional Edition

The menu item Diff and Merge | Support Recently Compared Pairs lets you enable or disable the "recently compared pairs" feature. More specifically, if this option is on, a history of the most recently compared files or directories is kept whenever you compare a pair of files or directories. You can select any recently compared file or directory from the drop-down list at the top of the comparison window, for example:

Selecting an item from the list above causes the "Recently Compared Pairs" dialog box to appear. This dialog box lists all the files (or directories, if applicable) with which the selected entry was compared recently, for example:

To compare the file or directory with any of the recently compared items, select the corresponding item, and click OK.