Nested family dissapear when setting up a view filter

[kigabor91]

Dear All,

I have spent hours to make this work, but I almost lost all hope.

I have a pipe fitting family (a sanitary pipe elbow). It has a nested family inside as per below:

It shows perfectly in a floor plan view in both coarse and fine detail mode:

As soon as I set up a view filter, to show elements with "sanitary", "domestic" and "fire" words in their "system classification" parameter, the nested family dissapears. As you can see below, the family itself is there, I can select it, however the nested family is not showing up making the fitting basically invisible. The elbow is connected to a sanitary system in my example.

The only difference between the two views is the filter: IF parameter "system classification" does not contain the word "sanitary" then make the element invisible. The filter works, so it turns down all heating pipes and fitting etc., but it turns off also the nested family in my sanitary pipe elbow.

These are the settings I use on the mentioned view filter: 

This is how the nested family looks like in edit mode:

How can I solve this issue so the family is visible just like it was before applying the view filter?

All element's "visibility" parameter is enabled in both parent and nested family.

I was thinking about if the nested family's system classification did not change to "sanitary" with the parent family. Is this possible? If so, is there a solution for that? So the nested family's system classification is equal to the parent family's system classification?

(I tried changing the nested family from "shared" to non-shared, it did not solve the problem.)

I attached the family itself. 

I hope I could describe the problem as clearly as possible. Thank you a lot in advance.

[iainsavage]

although the pipe fitting contains the correct classification the nested family does not (it has no classification), therefore the nested family is switched off by your filter