You have two ways to include all subcircuits
- In autogenerate symbol window, it has an option “Include Entire File”, select that and all subcircuits will be included in that one line netlist syntax in embedded symbol
- Or you just take advantage of using autogenerate symbol for generating symbol and pin. After symbol is generated, right click > symbol properties. In library, delete one line netlist and put your library file name there (e.g. Mylibrary.lib)