Abstractions
Any patch you have created and saved can be used as an object in another patch, just by typing the filename of your patch into an object box as if it were an object name. Patches used in this way are called abstractions.
To create an abstraction, you need to identify what information your patch always uses, and that its output is. Those things become the inlets and the outlets of your abstraction.

Creating an abstraction from a subpatcher
If you save your abstraction with either .pat or .maxpat file extensions, your abstractions will be available if autocompletion is enabled.

Once you create the abstraction file, you can return the main patcher, create a new object box, and type in the name of file (the extension is not required). Once you type the name of an abstraction once, it is added to the object box autocompletion list.