Define folder structure for your own symbols

Cabinet Layout tab > Devices group > Symbols

On the (User's symbols) tab in the Symbols window, you can define the folder structure yourself, i.e. you can create folders and subfolders and name and rename them as you like.

Create folders by right-clicking the empty space below the search field or the folder below which you want to create the new folder, and select Folder > New. Then enter the name for the new folder.
Rename folders by right-clicking the desired folder and selecting Folder > Rename. Then enter the new name.
Remove folders by right-clicking the desired folder and selecting Folder > Remove. Then confirm the removal by clicking Yes.

You can also create new folders in the symbol saving function (see Save your own symbols).