The file tree is located on the left hand side of the screen under the "FCS Files" header. It holds all the files you open as well as all the gates, stats, compensation, clusterings, and custom parameters you create.
If you have multiple files open, you can switch to a different file by clicking its name in the file tree.
You can use the Up/Down arrow keys on your keyboard to cycle through the files to compare their dot plots. You can use the Left/Right arrow keys to step in and out of different levels in the file tree hierarchy.
All entries in the file tree can be right clicked to bring up a menu with additional actions you can perform. The actions available are dependent on the type of entry.
Right Click on the entry in the file tree to open the actions menu. All entries support the Delete action through their actions menu. Alternatively, you can select the entry in the file tree and press the delete key on your keyboard. Note that deleting an entry will also delete any sub entries.
You can select multiple items by holding Ctrl/Cmd and clicking items in the file tree. The items will be highlighted green.
Drag and drop entries such as gates and stats on the file tree to copy them to other files in the tree. Additionally, if you drag and drop population entries to the plot you can overlay them, provided they have the same parameters.
You can also drag and drop multiple entries at a time by first selecting all entries you while holding Ctrl/Cmd and then drag and drop any of the green highlighted entries to the location you want.
You can select items to copy by holding Ctrl/Cmd and clicking items in the file tree. The items will be highlighted green. Then you can copy the green items you currently have selected with Ctrl/Cmd+c. Finally, if you click on another file in the file tree, you can press Ctrl/Cmd+v to paste the previously copied items onto that file.