This is very common, you memorize a path to a file or folder, you open up Vim and try to write what you've just memorized, but you are not 100% sure it's correct, so you close the editor and start over.
When you want the path completion feature, and you have a file
/home/ubuntu/my_folder/my_file and you are editing another file referencing to the path of the previous one:
Enter insert mode:
insert or do it the way you want.
/h. When the cursor is under
press Ctrlx and then Ctrlf so the editor will complete it to
/home/ because the pattern
/h is unique
Now, suppose you have two folders inside
and you want the path
Enter insert mode
/h and press Ctrlx and then Ctrlf . Now you have
Next add u after /home/ and press Ctrlx and then Ctrlf . Now, you have
/home/ubuntu/ because that path is unique.
/home/ubuntu/ and press Ctrlx and then Ctrlf . The editor will complete your word until
my_folder_ and you will see the directory tree so use the arrow keys to choose the one you want.