hello. I have a unique problem regarding toolbox in Solidworks and am open to any suggestions. 

The issue

At our company, we have standard hardware yet some hardware includes others

for example 

Part DB-01 can be sold alone but is also included in Q-WZDK along with other hardware 

I have created a part file for Q-WZDK because assemblies cannot be toolbox items

what I am hoping for is a solution to still show what is included in the assembly that is now a toolbox part 

ex. 

Q-WZDK  - includes DB-01, DB-02, WIRE 

I tried the list function but it only allows one selection. 

ideas I have had but would be strenuous 

add item included #1- DB-01 

               included #2- DB-02 

               included #3- WIRE 

The issue with this is getting it to show on a bom