In order to keep track of larger projects you should group your POUs, data types, visualizations, and global variables systematically in folders.
You can set up as many levels of folders as you want. If a plus sign is in front of
a closed folder symbol 
, then this folder contains objects and/or additional folders. With a click on the
plus sign the folder is opened and the subordinated objects appear. With a click on
the minus (which has replaced the plus sign) the folder can be closed again. In the
context menu you find the commands 'Expand nodes' and 'Collapse nodes' with the same
functions.
⮫ “'Expand nodes' 'Collapse nodes'”
With Drag&Drop you can move the objects as well as the folders within their object type. For this select the object and drag it with pressed left mouse button to the desired position.
You can create more folders with the command 'New folder'.
Folders have no influence on the program, but rather serve only to structure your project clearly.
