What I would like is when I find the object in MediaListF, I want to click on it, or Double click, and have it open SubtitleslistF to that one I have clicked on. I am sure I am missing something here.

You need a WHERE condition.

For Example:
   DoCmd.OpenForm "CustomerF",,, "CustomerID=" & lstCustomers

So n my case it would be:
DoCmd.OpenForm "SubtitlesListF",,, "MediaID=" & MediaListID?

If you are trying to double click the listbox and have it open. It would just be MediaID=" & YourListbox name, or MediaID=" & MediaList it looks like in your case. This assumes that you are bringing in the ID field into the listbox, and that it is the bound column of the listbox.

I really made a mistake from the very first with this database and I am regretting it now. This solution will not work with my database , as I have found out, which is OK since I was using this just to learn things. I am not depending on this for anything, but thanks anyway.