Assuming I'm interpretting correctly that subform2 is a subform on subform1
and that subform3 is a subform on subform2, you'd refer to controls on them
as
Forms!Main!Subform1.Form!Subform2.Form!Name1
and
Forms!Main!Subform1.Form!Subform2.Form!Subform3.Form!Name1
However, depending on how you added the forms as subforms, be aware that the
name of the subform control can be different than the name of the form being
used as a subform. It's the name of the subform control you need to use, not
the name of the form being used. See
http://www.mvps.org/access/forms/frm0031.htm at "The Access Web" for more on
this topic.
Since Subform2 is a subform on Subform1, what you put in the Link Parent
property must refer to controls on Subform1 and what you put in the Link
Child property refers to controls on Subform2. Similarly, since Subform3 is
a subform on Subform2, what you put in the Link Parent property must refer
to controls on Subform2 and what you put in the Link Child property refers
to controls on Subform3.

Signature
Doug Steele, Microsoft Access MVP
http://I.Am/DougSteele
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>I want to set up the following nested subforms:
>
[quoted text clipped - 22 lines]
> Thanks,
> Mark
Thanks for your help
> I want to set up the following nested subforms:
>
[quoted text clipped - 21 lines]
> Thanks,
> Mark