Did you name the cabinet component the same as the filename?
When you create components, they act as ‘little’ SketchUp model inside the main model and can be ‘saved as’ .skp files.
Options do appear in the main model, but if you edit a component, the options of the nested components show up.
If you opened the ‘saved as’ component file, it is like editing in the main model, you only see the ‘nested’ components.
Best to have a strategy when creating components:
Preceed the name of the working file with ‘WF_’, for instance,
Create the component(s) inside the Working File and save the components by rightclickjng on them and choose ‘Save As’, or save as collection through the component panel’s blue detail button.
Check his thread, also:
Edit: that artikel has a focus on placing models on the 3D Warehouse, but you can benefit from those rules and strategy’s and apply them to set up your own collection of components for use in your models and designs.