The problem is that you cannot use the connection in the nested family?

Into the family in the properties try to change the shared option and load again

You can try using connectors in shared families but there are big problems with that method (Complicated to explain but you will see if you try it.)
You can select the nested, shared, connector with TAB and connect to it but the pipe/duct locations come out totally wrong.
Really it is only possible to use connectors in the main, top level family.

Visibility for connectors has been on the ADsk MEP wish list for a looong time.... In the meantime there are a few methods that you can try;

1) Use an array to make your multiple connector extrusions. Use a parameter to control the number of extrusions. Place connectors on the extrusions in the main family. If you set the number of elements in the array to less (Min 2) then the connectors DO disappear in the project.

2) Move all the unused connectors onto the same point. When a user tries to connect they get a menu to choose which connector they want. (I use this a lot. For example a pump family with 2xSupply and 2xReturn connectors. Each 'connector' on the pump has supply or return and users can connect as they wish for different combinations of systems).

3) This ones a bit more complex but has lots of potential... Use nested, shared connector families in your main family. Put the main family in a small linked model. Use Copy-Monitor to copy the individual connector families into your project. This extracts the individual nested families out of the host family. Then you can connect to them all with no problem and changes to the positions in the main family (In the link) will come through to the project. (Unfortunately instance data does not come through but that is possible with Dynamo/macro)

4) Just expect users to know that they shouldnt use connectors that have no visible connection in the model......

So in other words.... yet another thing that adesk made unnecessarily complex and does almost...but not quite...what you want.

Hi, Thanks for all responses.

Shared Parameter doesn't work tried that before posting.

1) the problem with the array is because the connectors get place (1-center, 2 - @25% length & 75% , 3 20%60%80% and so on to 6 connections) so if 1 connection the array doesn't work, also it locks to ref lines which then causes parameters to not work when stretching

2)+3) sadly comes down to user error ( I know Dynamo, but asking somebody to use Dynamo is to Risky, maybe in 2017 with the new dynamo player ability that could be a possibility), we try to make the families as limited as possible to avoid skill level problems (sadly this happens more than you think)

4) looks like this is our go to for the time being, pity and shame on Autodesk I suppose, heard from co-worker Revit 2012 had visibility parameters for connections.

I will keep looking at ways