Project and Structure navigation splitting in PhpStorm 7/8/9

Question

Anyone know how to make project and structure navigation set in splitting mode?

See images ( I was able doing this, but don't know how )

Answer 1

As of version 2019.1, PHPStorm tool windows no longer behave the way the other answers say, that is, there is no explicit "split mode". Instead, it uses the location of the tab; you can no longer split tool windows if they are in the same tab group, but you can display two tool panes by putting them in different groups. So if you're looking for the standard projects half-pane at the top, and structure at the bottom, put structure in the top left group, and structure in the bottom left, and then enable them both - and the view will split.

To reiterate – if you have both project and structure in top left, there is no way to split them; you must move the tab.

Answer 2

Sure, just grab your "Structure" tool window button (the one on the left side, that has "7" in the title) and drag it to the bottom part of the same side.

Alternatively just right click on tool window button or title bar and choose "Split Mode" -- it will move it to the opposite part of the same side (e.g. will move from Left Top to Left Bottom -- just as per your image).

Official manual page.