I hate tabs. I prefer side-by-side subforms. But if you MUST keep it with tabs, and nobody else has a solution, let me know in a couple days and I'll figure something out for you. I don't use tabs. I don't like them. So I don't know off-hand how to do this without experimenting.

I rarely use Tabs so took a little figuring out. See screenshot and change the names where necessary.

Sorry, forgot to put in screenshot - set the Link Master/Child fields of the sub form on page 2 to your ID field.

Thanks Kevin,

Let clarify:  
1.  is your TabF the "master form" name or the tab control name?.
2. see pic wrt unbound customerID ( I change names so that I dont confuse my self)...I created an unbound on the subform which updated as I moved from record to record.....but I could never get the value "out of" the subform.

The unbound fields are SFAdventureID (it works and is on the subform)
MFAdventureID is on the mainform and I could never get it to recognize any of my code....Me. and Forms! etc...

Private Sub Form_Current()
    Forms!AdventureT_Frm!AdventureID = AdventureID
    ' 1. Subform name above
    ' 2. Forms!Adventure_TabFrm!AdventureID = AdventureID (this is the Mainform name)
    ' 3. Forms!TabForm!AdventureID = AdventureID (this is the tab control  name)
    ' All gave the same warning cannot fine form name
    MsgBox AdventureID
End Sub

Geez, after I removed my code in the MFAdventureID , then the on current updated my MFAdventureID,  so the first step is now working,   I have an unbound  with the ID value from the tab 0 ,,  I do not understand

forms!Adventure_TabFrm! {what is Tab1 in your code}....tab1.pages.item(1).SetfFocus.   and what is item(1)....not sure of the logic of getting to  the 2nd tab (tab1 ??) and then selecting records based on MFAdventureID (unbound value)

Tab1 is the name of my Tab Control.
Item(1) is the second page (Tab).

They are zero-based meaning:
   The first tab has an index of 0
   The second tab has an index of 1
   ...and so on.

Ok, I subsisted my tab control name and now the tab1 (2nd tab) opens but it is at the first record and not using the unbound filed ID value to select records....

and I am still getting the "cant build a link between unbound forms".....

Kevin, Thanks I have it working now.  I misunderstood your instruction:
"Sorry, forgot to put in screenshot - set the Link Master/Child fields of the sub form on page 2 to your ID field."
the Link Master should reference the unbound "ID" field name which in my case is MFAdventureID.

again thanks , I think I am cooking in oil now.

I'm glad Kevin got you working because I hate tabs.

Did I mention... I hate tabs? :)