The key is
- To make the parameters in the first family 'Instance' not 'Type', load it into the 2nd family(host)
- Then in the 2nd family(host) create a duplicate parameter in the 'Type' dialogue box.
- Now select the 1st family that's placed in the 2nd one and in the 'Properties' dialogue select the grey box to the right and make the parameter equal the new parameter, it should then grey out the value.
- Load 2nd family into the project and now you should be able to modify the parameters of the first family even though its not directly loaded into the project.
- Selection the object or geometry
- In the Properties dialogue box beside the visibility setting click the grey box
- Create a new 'yes/no' parameter(automatically selected) decide weather its instance or type
- Load into project environment and play with the yes/no for visibility setting