Create a block for each suppliers and each diameter

[NeoLitik]

Hello.

I have piping components (flanges) from several different suppliers.
I am trying to make a block with a drop down list including each supplier, and for each supplier a sub drop down menu to display each diameter, and for each diameter again a drop down menu with the pressure rating for example.

For the moment I just manage to have a drop down menu (not nested) with different visibility.

I can't nest the drop-down menus :'(

Unless I'm mistaken: I can't use a parameter manager because the equipment doesn't have standard shapes

so I try to do something like this (simplified) (see picture)

thank in advance to take time to answer at my question

regards