It is strongly advised that humans only perform one task at a time. This is said because (most) humans cannot multitask, and hence if they attempt to do so, they make mistakes. The same is the case with you, dear.
In the event that you have to work on a project that demands you modify a number of files at once, there is a big chance that you might forget which editor you came from and where to go if the current file being scanned is not the correct copy.
In PhpStorm, you can go back to the previous editor / next editor / choose from the list of open editors by remembering (and obviously using) keymaps. To do so, perform the following steps:
Use Alt + Left for previous editor.
If you want to move to the next editor, use Alt + Right.
A facility that allows you to move to any part of the code or any class in the open project is available in PhpStorm. This facility enables you to access at random any part of any class or any part of any file that is open in the currently open project, as shown in the following screenshot:
And, as usual, there are some customizations involved in the behavior of PhpStorm. There is a filter symbol. Clicking on the filter symbol, quite implicitly, allows you to filter the search criteria. You can tell PhpStorm not to look in a certain file or resource type by simply unchecking the unwanted file or resource type. Refer to the preceding screenshot for clarity.
To enable random access, every item needs to be added to the index. You can now give credit to the PhpStorm development team for developing this powerful indexing system.